diff --git a/src/main/java/io/vavr/CheckedConsumer.java b/src/main/java/io/vavr/CheckedConsumer.java
index d8bf47290..1f630c857 100644
--- a/src/main/java/io/vavr/CheckedConsumer.java
+++ b/src/main/java/io/vavr/CheckedConsumer.java
@@ -79,7 +79,6 @@ static <T> CheckedConsumer<T> of(CheckedConsumer<T> methodReference) {
      * @throws NullPointerException if {@code after} is null
      */
     default CheckedConsumer<T> andThen(CheckedConsumer<? super T> after) {
-        Objects.requireNonNull(after, "after is null");
         return (T t) -> { accept(t); after.accept(t); };
     }
 
diff --git a/src/main/java/io/vavr/Lazy.java b/src/main/java/io/vavr/Lazy.java
index b7bb3de21..8fa532c46 100644
--- a/src/main/java/io/vavr/Lazy.java
+++ b/src/main/java/io/vavr/Lazy.java
@@ -103,7 +103,6 @@ public static <T> Lazy<T> narrow(Lazy<? extends T> lazy) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Lazy<T> of(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         if (supplier instanceof Lazy) {
             return (Lazy<T>) supplier;
         } else {
@@ -122,7 +121,6 @@ public static <T> Lazy<T> of(Supplier<? extends T> supplier) {
      */
     @SuppressWarnings("Convert2MethodRef") // TODO should be fixed in JDK 9 and Idea
     public static <T> Lazy<Seq<T>> sequence(Iterable<? extends Lazy<? extends T>> values) {
-        Objects.requireNonNull(values, "values is null");
         return Lazy.of(() -> Vector.ofAll(values).map(lazy -> lazy.get()));
     }
 
@@ -137,8 +135,6 @@ public static <T> Lazy<Seq<T>> sequence(Iterable<? extends Lazy<? extends T>> va
      */
     @SuppressWarnings("unchecked")
     public static <T> T val(Supplier<? extends T> supplier, Class<T> type) {
-        Objects.requireNonNull(supplier, "supplier is null");
-        Objects.requireNonNull(type, "type is null");
         if (!type.isInterface()) {
             throw new IllegalArgumentException("type has to be an interface");
         }
@@ -148,13 +144,11 @@ public static <T> T val(Supplier<? extends T> supplier, Class<T> type) {
     }
 
     public Option<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final T v = get();
         return predicate.test(v) ? Option.some(v) : Option.none();
     }
 
     public Option<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
@@ -245,7 +239,6 @@ public Lazy<T> peek(Consumer<? super T> action) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super Lazy<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
diff --git a/src/main/java/io/vavr/Predicates.java b/src/main/java/io/vavr/Predicates.java
index 041fe8213..b181a18d5 100644
--- a/src/main/java/io/vavr/Predicates.java
+++ b/src/main/java/io/vavr/Predicates.java
@@ -64,7 +64,6 @@ private Predicates() {
     @SuppressWarnings({ "unchecked", "varargs" })
     @SafeVarargs
     public static <T> Predicate<T> allOf(Predicate<T>... predicates) {
-        Objects.requireNonNull(predicates, "predicates is null");
         return t -> List.of(predicates).foldLeft(true, (bool, pred) -> bool && pred.test(t));
     }
 
@@ -88,7 +87,6 @@ public static <T> Predicate<T> allOf(Predicate<T>... predicates) {
     @SuppressWarnings({ "unchecked", "varargs" })
     @SafeVarargs
     public static <T> Predicate<T> anyOf(Predicate<T>... predicates) {
-        Objects.requireNonNull(predicates, "predicates is null");
         return t -> List.of(predicates).find(pred -> pred.test(t)).isDefined();
     }
 
@@ -108,7 +106,6 @@ public static <T> Predicate<T> anyOf(Predicate<T>... predicates) {
      * @throws NullPointerException if {@code predicate} is null
      */
     public static <T> Predicate<Iterable<T>> exists(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return iterable -> Iterator.ofAll(iterable).exists(predicate);
     }
 
@@ -128,7 +125,6 @@ public static <T> Predicate<Iterable<T>> exists(Predicate<? super T> predicate)
      * @throws NullPointerException if {@code predicate} is null
      */
     public static <T> Predicate<Iterable<T>> forAll(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return iterable -> Iterator.ofAll(iterable).forAll(predicate);
     }
 
@@ -148,7 +144,6 @@ public static <T> Predicate<Iterable<T>> forAll(Predicate<? super T> predicate)
      */
     // DEV-NOTE: We need Class<? extends T> instead of Class<T>, see {@link TryTest#shouldRecoverSuccessUsingCase()}
     public static <T> Predicate<T> instanceOf(Class<? extends T> type) {
-        Objects.requireNonNull(type, "type is null");
         return obj -> obj != null && type.isAssignableFrom(obj.getClass());
     }
 
@@ -188,7 +183,6 @@ public static <T> Predicate<T> is(T value) {
     @SuppressWarnings({ "unchecked", "varargs" })
     @SafeVarargs
     public static <T> Predicate<T> isIn(T... values) {
-        Objects.requireNonNull(values, "values is null");
         return obj -> List.of(values).find(value -> Objects.equals(value, obj)).isDefined();
     }
 
@@ -245,7 +239,6 @@ public static <T> Predicate<T> isNull() {
     @SuppressWarnings({ "unchecked", "varargs" })
     @SafeVarargs
     public static <T> Predicate<T> noneOf(Predicate<T>... predicates) {
-        Objects.requireNonNull(predicates, "predicates is null");
         return anyOf(predicates).negate();
     }
 
@@ -271,7 +264,6 @@ public static <T> Predicate<T> noneOf(Predicate<T>... predicates) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Predicate<T> not(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return (Predicate<T>) predicate.negate();
     }
 
diff --git a/src/main/java/io/vavr/Value.java b/src/main/java/io/vavr/Value.java
index 0eaacbea3..f124e953c 100644
--- a/src/main/java/io/vavr/Value.java
+++ b/src/main/java/io/vavr/Value.java
@@ -313,7 +313,6 @@ default boolean eq(Object o) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default boolean exists(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (T t : this) {
             if (predicate.test(t)) {
                 return true;
@@ -330,7 +329,6 @@ default boolean exists(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default boolean forAll(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return !exists(predicate.negate());
     }
 
@@ -342,7 +340,6 @@ default boolean forAll(Predicate<? super T> predicate) {
      */
     @Override
     default void forEach(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         for (T t : this) {
             action.accept(t);
         }
@@ -383,7 +380,6 @@ default T getOrElse(T other) {
      * @throws NullPointerException if supplier is null
      */
     default T getOrElse(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isEmpty() ? supplier.get() : get();
     }
 
@@ -397,7 +393,6 @@ default T getOrElse(Supplier<? extends T> supplier) {
      * @throws X                    if no value is present
      */
     default <X extends Throwable> T getOrElseThrow(Supplier<X> supplier) throws X {
-        Objects.requireNonNull(supplier, "supplier is null");
         if (isEmpty()) {
             throw supplier.get();
         } else {
@@ -413,7 +408,6 @@ default <X extends Throwable> T getOrElseThrow(Supplier<X> supplier) throws X {
      * @throws NullPointerException if supplier is null
      */
     default T getOrElseTry(CheckedFunction0<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isEmpty() ? Try.of(supplier).get() : get();
     }
 
@@ -612,7 +606,6 @@ default <U> Validation<T, U> toInvalid(U value) {
      */
     @Deprecated
     default <U> Validation<T, U> toInvalid(Supplier<? extends U> valueSupplier) {
-        Objects.requireNonNull(valueSupplier, "valueSupplier is null");
         return isEmpty() ? Validation.valid(valueSupplier.get()) : Validation.invalid(get());
     }
 
@@ -672,7 +665,6 @@ default Object[] toJavaArray() {
     @Deprecated
     @SuppressWarnings("unchecked")
     default T[] toJavaArray(Class<T> componentType) {
-        Objects.requireNonNull(componentType, "componentType is null");
         if (componentType.isPrimitive()) {
             final Class<?> boxedType =
                     componentType == boolean.class ? Boolean.class :
@@ -852,8 +844,6 @@ default <K, V> java.util.Map<K, V> toJavaMap(Function<? super T, ? extends Tuple
      * @return a new {@code java.util.Map} of type {@code MAP}
      */
     default <K, V, MAP extends java.util.Map<K, V>> MAP toJavaMap(Supplier<MAP> factory, Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return toJavaMap(factory, t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)));
     }
 
@@ -883,7 +873,6 @@ default <K, V, MAP extends java.util.Map<K, V>> MAP toJavaMap(Supplier<MAP> fact
      * @return a new {@code java.util.Map} of type {@code MAP}
      */
     default <K, V, MAP extends java.util.Map<K, V>> MAP toJavaMap(Supplier<MAP> factory, Function<? super T, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         final MAP map = factory.get();
         if (!isEmpty()) {
             if (isSingleValued()) {
@@ -1048,7 +1037,6 @@ default <R> Either<T, R> toLeft(R right) {
      */
     @Deprecated
     default <R> Either<T, R> toLeft(Supplier<? extends R> right) {
-        Objects.requireNonNull(right, "right is null");
         return isEmpty() ? Either.right(right.get()) : Either.left(get());
     }
 
@@ -1071,8 +1059,6 @@ default List<T> toList() {
      * @return A new {@link HashMap}.
      */
     default <K, V> Map<K, V> toMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return toMap(t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)));
     }
 
@@ -1085,7 +1071,6 @@ default <K, V> Map<K, V> toMap(Function<? super T, ? extends K> keyMapper, Funct
      * @return A new {@link HashMap}.
      */
     default <K, V> Map<K, V> toMap(Function<? super T, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         final Function<Tuple2<? extends K, ? extends V>, Map<K, V>> ofElement = HashMap::of;
         final Function<Iterable<Tuple2<? extends K, ? extends V>>, Map<K, V>> ofAll = HashMap::ofEntries;
         return ValueModule.toMap(this, HashMap.empty(), ofElement, ofAll, f);
@@ -1101,8 +1086,6 @@ default <K, V> Map<K, V> toMap(Function<? super T, ? extends Tuple2<? extends K,
      * @return A new {@link LinkedHashMap}.
      */
     default <K, V> Map<K, V> toLinkedMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return toLinkedMap(t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)));
     }
 
@@ -1115,7 +1098,6 @@ default <K, V> Map<K, V> toLinkedMap(Function<? super T, ? extends K> keyMapper,
      * @return A new {@link LinkedHashMap}.
      */
     default <K, V> Map<K, V> toLinkedMap(Function<? super T, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         final Function<Tuple2<? extends K, ? extends V>, Map<K, V>> ofElement = LinkedHashMap::of;
         final Function<Iterable<Tuple2<? extends K, ? extends V>>, Map<K, V>> ofAll = LinkedHashMap::ofEntries;
         return ValueModule.toMap(this, LinkedHashMap.empty(), ofElement, ofAll, f);
@@ -1131,8 +1113,6 @@ default <K, V> Map<K, V> toLinkedMap(Function<? super T, ? extends Tuple2<? exte
      * @return A new {@link TreeMap}.
      */
     default <K extends Comparable<? super K>, V> SortedMap<K, V> toSortedMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return toSortedMap(t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)));
     }
 
@@ -1145,7 +1125,6 @@ default <K extends Comparable<? super K>, V> SortedMap<K, V> toSortedMap(Functio
      * @return A new {@link TreeMap}.
      */
     default <K extends Comparable<? super K>, V> SortedMap<K, V> toSortedMap(Function<? super T, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         return toSortedMap(Comparator.naturalOrder(), f);
     }
 
@@ -1160,9 +1139,6 @@ default <K extends Comparable<? super K>, V> SortedMap<K, V> toSortedMap(Functio
      * @return A new {@link TreeMap}.
      */
     default <K, V> SortedMap<K, V> toSortedMap(Comparator<? super K> comparator, Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return toSortedMap(comparator, t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)));
     }
 
@@ -1176,8 +1152,6 @@ default <K, V> SortedMap<K, V> toSortedMap(Comparator<? super K> comparator, Fun
      * @return A new {@link TreeMap}.
      */
     default <K, V> SortedMap<K, V> toSortedMap(Comparator<? super K> comparator, Function<? super T, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(f, "f is null");
         final Function<Tuple2<? extends K, ? extends V>, SortedMap<K, V>> ofElement = t -> TreeMap.of(comparator, t);
         final Function<Iterable<Tuple2<? extends K, ? extends V>>, SortedMap<K, V>> ofAll = t -> TreeMap.ofEntries(comparator, t);
         return ValueModule.toMap(this, TreeMap.empty(comparator), ofElement, ofAll, f);
@@ -1219,7 +1193,6 @@ default <L> Either<L, T> toEither(L left) {
      * @return A new {@link Either}.
      */
     default <L> Either<L, T> toEither(Supplier<? extends L> leftSupplier) {
-        Objects.requireNonNull(leftSupplier, "leftSupplier is null");
         if (this instanceof Either) {
             return ((Either<?, T>) this).mapLeft(ignored -> leftSupplier.get());
         } else {
@@ -1250,7 +1223,6 @@ default <E> Validation<E, T> toValidation(E invalid) {
      * @return A new {@link Validation}.
      */
     default <E> Validation<E, T> toValidation(Supplier<? extends E> invalidSupplier) {
-        Objects.requireNonNull(invalidSupplier, "invalidSupplier is null");
         if (this instanceof Validation) {
             return ((Validation<?, T>) this).mapError(ignored -> invalidSupplier.get());
         } else {
@@ -1291,7 +1263,6 @@ default PriorityQueue<T> toPriorityQueue() {
      * @return A new {@link PriorityQueue}.
      */
     default PriorityQueue<T> toPriorityQueue(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final PriorityQueue<T> empty = PriorityQueue.empty(comparator);
         final Function<T, PriorityQueue<T>> of = value -> PriorityQueue.of(comparator, value);
         final Function<Iterable<T>, PriorityQueue<T>> ofAll = values -> PriorityQueue.ofAll(comparator, values);
@@ -1324,7 +1295,6 @@ default <L> Either<L, T> toRight(L left) {
      */
     @Deprecated
     default <L> Either<L, T> toRight(Supplier<? extends L> left) {
-        Objects.requireNonNull(left, "left is null");
         return isEmpty() ? Either.left(left.get()) : Either.right(get());
     }
 
@@ -1372,7 +1342,6 @@ default SortedSet<T> toSortedSet() throws ClassCastException {
      * @return A new {@link TreeSet}.
      */
     default SortedSet<T> toSortedSet(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return ValueModule.toTraversable(this, TreeSet.empty(comparator), value -> TreeSet.of(comparator, value), values -> TreeSet.ofAll(comparator, values));
     }
 
@@ -1411,7 +1380,6 @@ default Try<T> toTry() {
      * @return A new {@link Try}.
      */
     default Try<T> toTry(Supplier<? extends Throwable> ifEmpty) {
-        Objects.requireNonNull(ifEmpty, "ifEmpty is null");
         return isEmpty() ? Try.failure(ifEmpty.get()) : toTry();
     }
 
@@ -1463,7 +1431,6 @@ default <E> Validation<E, T> toValid(E error) {
      */
     @Deprecated
     default <E> Validation<E, T> toValid(Supplier<? extends E> errorSupplier) {
-        Objects.requireNonNull(errorSupplier, "errorSupplier is null");
         return isEmpty() ? Validation.invalid(errorSupplier.get()) : Validation.valid(get());
     }
 
diff --git a/src/main/java/io/vavr/collection/AbstractMultimap.java b/src/main/java/io/vavr/collection/AbstractMultimap.java
index a38dd542f..9f961aae3 100644
--- a/src/main/java/io/vavr/collection/AbstractMultimap.java
+++ b/src/main/java/io/vavr/collection/AbstractMultimap.java
@@ -86,8 +86,6 @@ public Map<K, Traversable<V>> asMap() {
 
     @Override
     public <K2, V2> Multimap<K2, V2> bimap(Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         final Iterator<Tuple2<K2, V2>> entries = iterator().map(entry -> Tuple.of(keyMapper.apply(entry._1), valueMapper.apply(entry._2)));
         return createFromEntries(entries);
     }
@@ -104,7 +102,6 @@ public ContainerType getContainerType() {
 
     @Override
     public <K2, V2> Multimap<K2, V2> flatMap(BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2, V2>>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(this.emptyInstance(), (acc, entry) -> {
             for (Tuple2<? extends K2, ? extends V2> mappedEntry : mapper.apply(entry._1, entry._2)) {
                 acc = acc.put(mappedEntry);
@@ -131,13 +128,11 @@ public Set<K> keySet() {
 
     @Override
     public <K2, V2> Multimap<K2, V2> map(BiFunction<? super K, ? super V, Tuple2<K2, V2>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(this.emptyInstance(), (acc, entry) -> acc.put(mapper.apply(entry._1, entry._2)));
     }
 
     @Override
     public <V2> Multimap<K, V2> mapValues(Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return map((k, v) -> Tuple.of(k, valueMapper.apply(v)));
     }
 
@@ -151,7 +146,6 @@ public M put(K key, V value) {
 
     @Override
     public M put(Tuple2<? extends K, ? extends V> entry) {
-        Objects.requireNonNull(entry, "entry is null");
         return put(entry._1, entry._2);
     }
 
@@ -201,14 +195,12 @@ public M distinct() {
     @SuppressWarnings("unchecked")
     @Override
     public M distinctBy(Comparator<? super Tuple2<K, V>> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return (M) (isEmpty() ? this : createFromEntries(iterator().distinctBy(comparator)));
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public <U> M distinctBy(Function<? super Tuple2<K, V>, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return (M) (isEmpty() ? this : createFromEntries(iterator().distinctBy(keyExtractor)));
     }
 
@@ -238,21 +230,18 @@ public M dropRight(int n) {
 
     @Override
     public M dropUntil(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public M dropWhile(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return (M) (isEmpty() ? this : createFromEntries(iterator().dropWhile(predicate)));
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public M filter(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return (M) this;
         } else {
@@ -263,43 +252,36 @@ public M filter(Predicate<? super Tuple2<K, V>> predicate) {
 
     @Override
     public M filterNot(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
     @Override
     public M filter(BiPredicate<? super K, ? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(t -> predicate.test(t._1, t._2));
     }
 
     @Override
     public M filterNot(BiPredicate<? super K, ? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterNot(t -> predicate.test(t._1, t._2));
     }
 
     @Override
     public M filterKeys(Predicate<? super K> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(t -> predicate.test(t._1));
     }
 
     @Override
     public M filterNotKeys(Predicate<? super K> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterNot(t -> predicate.test(t._1));
     }
 
     @Override
     public M filterValues(Predicate<? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(t -> predicate.test(t._2));
     }
 
     @Override
     public M filterNotValues(Predicate<? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterNot(t -> predicate.test(t._2));
     }
 
@@ -369,7 +351,6 @@ public Tuple2<K, V> last() {
     @SuppressWarnings("unchecked")
     @Override
     public M merge(Multimap<? extends K, ? extends V> that) {
-        Objects.requireNonNull(that, "that is null");
         if (isEmpty()) {
             return (M) createFromEntries(that);
         } else if (that.isEmpty()) {
@@ -382,8 +363,6 @@ public M merge(Multimap<? extends K, ? extends V> that) {
     @SuppressWarnings("unchecked")
     @Override
     public <K2 extends K, V2 extends V> M merge(Multimap<K2, V2> that, BiFunction<Traversable<V>, Traversable<V2>, Traversable<V>> collisionResolution) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(collisionResolution, "collisionResolution is null");
         if (isEmpty()) {
             return (M) createFromEntries(that);
         } else if (that.isEmpty()) {
@@ -430,7 +409,6 @@ public M orElse(Supplier<? extends Iterable<? extends Tuple2<K, V>>> supplier) {
     @SuppressWarnings("unchecked")
     @Override
     public Tuple2<M, M> partition(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final java.util.List<Tuple2<K, V>> left = new java.util.ArrayList<>();
         final java.util.List<Tuple2<K, V>> right = new java.util.ArrayList<>();
         for (Tuple2<K, V> entry : this) {
@@ -442,7 +420,6 @@ public Tuple2<M, M> partition(Predicate<? super Tuple2<K, V>> predicate) {
     @SuppressWarnings("unchecked")
     @Override
     public M peek(Consumer<? super Tuple2<K, V>> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -452,8 +429,6 @@ public M peek(Consumer<? super Tuple2<K, V>> action) {
     @SuppressWarnings("unchecked")
     @Override
     public M replace(Tuple2<K, V> currentElement, Tuple2<K, V> newElement) {
-        Objects.requireNonNull(currentElement, "currentElement is null");
-        Objects.requireNonNull(newElement, "newElement is null");
         return (M) (containsKey(currentElement._1) ? remove(currentElement._1, currentElement._2).put(newElement) : this);
     }
 
@@ -483,7 +458,6 @@ public M replaceAll(BiFunction<? super K, ? super V, ? extends V> function) {
     @SuppressWarnings("unchecked")
     @Override
     public M retainAll(Iterable<? extends Tuple2<K, V>> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return (M) createFromEntries(back.flatMap(t -> t._2.map(v -> Tuple.of(t._1, v))).retainAll(elements));
     }
 
@@ -513,7 +487,6 @@ public Iterator<M> sliding(int size, int step) {
     @SuppressWarnings("unchecked")
     @Override
     public Tuple2<M, M> span(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Tuple2<Iterator<Tuple2<K, V>>, Iterator<Tuple2<K, V>>> t = iterator().span(predicate);
         return Tuple.of((M) createFromEntries(t._1), (M) createFromEntries(t._2));
     }
@@ -559,14 +532,12 @@ public M takeRight(int n) {
 
     @Override
     public M takeUntil(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @SuppressWarnings("unchecked")
     @Override
     public M takeWhile(Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Multimap<K, V> taken = createFromEntries(iterator().takeWhile(predicate));
         return (M) (taken.length() == length() ? this : taken);
     }
diff --git a/src/main/java/io/vavr/collection/AbstractQueue.java b/src/main/java/io/vavr/collection/AbstractQueue.java
index aaec975ca..ba31ca8fc 100644
--- a/src/main/java/io/vavr/collection/AbstractQueue.java
+++ b/src/main/java/io/vavr/collection/AbstractQueue.java
@@ -77,7 +77,6 @@ public Option<Tuple2<T, Q>> dequeueOption() {
      */
     @SuppressWarnings("unchecked")
     public Q enqueue(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return enqueueAll(List.of(elements));
     }
 
@@ -116,7 +115,6 @@ public Option<T> peekOption() {
 
     @Override
     public Q dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
@@ -175,7 +173,6 @@ public Q removeAll(Iterable<? extends T> elements) {
 
     @Override
     public Q takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeUntil(predicate.negate());
     }
 
@@ -185,7 +182,6 @@ public Q takeWhile(Predicate<? super T> predicate) {
     @SuppressWarnings("unchecked")
     @Override
     public Q peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
diff --git a/src/main/java/io/vavr/collection/Array.java b/src/main/java/io/vavr/collection/Array.java
index 102eb1c31..ead41c4ee 100644
--- a/src/main/java/io/vavr/collection/Array.java
+++ b/src/main/java/io/vavr/collection/Array.java
@@ -129,7 +129,6 @@ public static <T> Array<T> of(T element) {
     @SuppressWarnings("varargs")
     @SafeVarargs
     public static <T> Array<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return wrap(copyOf(elements, elements.length));
     }
 
@@ -151,7 +150,6 @@ public static <T> Array<T> of(T... elements) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Array<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof Array) {
             return (Array<T>) elements;
         }
@@ -175,7 +173,6 @@ public static <T> Array<T> ofAll(Iterable<? extends T> elements) {
      * @return An Array containing the given elements in the same order.
      */
     public static <T> Array<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return wrap(javaStream.toArray());
     }
 
@@ -191,7 +188,6 @@ public static <T> Array<T> ofAll(java.util.stream.Stream<? extends T> javaStream
      * @throws NullPointerException if elements is null
      */
     public static Array<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -207,7 +203,6 @@ public static Array<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -223,7 +218,6 @@ public static Array<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -238,7 +232,6 @@ public static Array<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -254,7 +247,6 @@ public static Array<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -270,7 +262,6 @@ public static Array<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -286,7 +277,6 @@ public static Array<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -302,7 +292,6 @@ public static Array<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Array<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -321,7 +310,6 @@ public static Array<Short> ofAll(short... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> Array<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return io.vavr.collection.Collections.tabulate(n, f, empty(), Array::of);
     }
 
@@ -335,7 +323,6 @@ public static <T> Array<T> tabulate(int n, Function<? super Integer, ? extends T
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> Array<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return io.vavr.collection.Collections.fill(n, s, empty(), Array::of);
     }
 
@@ -673,7 +660,6 @@ public Array<T> append(T element) {
 
     @Override
     public Array<T> appendAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() && elements instanceof Array) {
             @SuppressWarnings("unchecked")
             final Array<T> array = (Array<T>) elements;
@@ -793,14 +779,12 @@ public Array<T> distinct() {
 
     @Override
     public Array<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final java.util.Set<T> seen = new java.util.TreeSet<>(comparator);
         return filter(seen::add);
     }
 
     @Override
     public <U> Array<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         final java.util.Set<U> seen = new java.util.HashSet<>();
         return filter(t -> seen.add(keyExtractor.apply(t)));
     }
@@ -825,7 +809,6 @@ public Array<T> dropUntil(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropUntil(predicate.negate());
     }
 
@@ -847,13 +830,11 @@ public Array<T> dropRightUntil(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> dropRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
     @Override
     public Array<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final java.util.List<T> list = new ArrayList<>();
         for (T t : this) {
             if (predicate.test(t)) {
@@ -871,13 +852,11 @@ public Array<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Collections.filterNot(this, predicate);
     }
 
     @Override
     public <U> Array<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -1015,7 +994,6 @@ public int length() {
 
     @Override
     public <U> Array<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         final Object[] arr = new Object[length()];
         for (int i = 0; i < delegate.length; i++) {
             arr[i] = mapper.apply(get(i));
@@ -1065,7 +1043,6 @@ public Array<T> patch(int from, Iterable<? extends T> that, int replaced) {
 
     @Override
     public Tuple2<Array<T>, Array<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final java.util.List<T> left = new ArrayList<>(), right = new ArrayList<>();
         for (T t : this) {
             (predicate.test(t) ? left : right).add(t);
@@ -1075,7 +1052,6 @@ public Tuple2<Array<T>, Array<T>> partition(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -1126,7 +1102,6 @@ public Array<T> remove(T element) {
 
     @Override
     public Array<T> removeFirst(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int found = -1;
         for (int i = 0; i < length(); i++) {
             final T value = get(i);
@@ -1144,7 +1119,6 @@ public Array<T> removeFirst(Predicate<T> predicate) {
 
     @Override
     public Array<T> removeLast(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int found = -1;
         for (int i = length() - 1; i >= 0; i--) {
             final T value = get(i);
@@ -1336,14 +1310,12 @@ public Tuple2<Array<T>, Array<T>> splitAt(int n) {
 
     @Override
     public Tuple2<Array<T>, Array<T>> splitAt(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Array<T> init = takeWhile(predicate.negate());
         return Tuple.of(init, drop(init.length()));
     }
 
     @Override
     public Tuple2<Array<T>, Array<T>> splitAtInclusive(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = 0; i < delegate.length; i++) {
             final T value = get(i);
             if (predicate.test(value)) {
@@ -1359,7 +1331,6 @@ public Tuple2<Array<T>, Array<T>> splitAtInclusive(Predicate<? super T> predicat
 
     @Override
     public Tuple2<Array<T>, Array<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Tuple.of(takeWhile(predicate), dropWhile(predicate));
     }
 
@@ -1420,7 +1391,6 @@ public Array<T> takeUntil(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeUntil(predicate.negate());
     }
 
@@ -1444,7 +1414,6 @@ public Array<T> takeRightUntil(Predicate<? super T> predicate) {
 
     @Override
     public Array<T> takeRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightUntil(predicate.negate());
     }
 
@@ -1457,7 +1426,6 @@ public Array<T> takeRightWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super Array<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1474,7 +1442,6 @@ public Array<T> update(int index, T element) {
 
     @Override
     public Array<T> update(int index, Function<? super T, ? extends T> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         return update(index, updater.apply(get(index)));
     }
 
@@ -1485,14 +1452,11 @@ public <U> Array<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> Array<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> Array<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -1503,7 +1467,6 @@ public Array<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> Array<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/BitSet.java b/src/main/java/io/vavr/collection/BitSet.java
index d7ae93fab..ed32ea297 100644
--- a/src/main/java/io/vavr/collection/BitSet.java
+++ b/src/main/java/io/vavr/collection/BitSet.java
@@ -92,22 +92,18 @@ public final BitSet<T> of(T... values) {
         }
 
         public BitSet<T> ofAll(Iterable<? extends T> values) {
-            Objects.requireNonNull(values, "values is null");
             return empty().addAll(values);
         }
 
         public BitSet<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-            Objects.requireNonNull(javaStream, "javaStream is null");
             return empty().addAll(Iterator.ofAll(javaStream.iterator()));
         }
 
         public BitSet<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-            Objects.requireNonNull(f, "f is null");
             return empty().addAll(Collections.tabulate(n, f));
         }
 
         public BitSet<T> fill(int n, Supplier<? extends T> s) {
-            Objects.requireNonNull(s, "s is null");
             return empty().addAll(Collections.fill(n, s));
         }
     }
@@ -200,7 +196,6 @@ public static BitSet<Integer> ofAll(java.util.stream.Stream<Integer> javaStream)
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.withRelations(i -> i != 0, b -> b ? 1 : 0).ofAll(Iterator.ofAll(elements));
     }
 
@@ -212,7 +207,6 @@ public static BitSet<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.withBytes().ofAll(Iterator.ofAll(elements));
     }
 
@@ -224,7 +218,6 @@ public static BitSet<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.withCharacters().ofAll(Iterator.ofAll(elements));
     }
 
@@ -236,7 +229,6 @@ public static BitSet<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -248,7 +240,6 @@ public static BitSet<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.withLongs().ofAll(Iterator.ofAll(elements));
     }
 
@@ -260,7 +251,6 @@ public static BitSet<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static BitSet<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return BitSet.withShorts().ofAll(Iterator.ofAll(elements));
     }
 
@@ -358,7 +348,6 @@ public static BitSet<Long> rangeClosedBy(long from, long toInclusive, long step)
 
     @Override
     public final <R> SortedSet<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
         return TreeSet.ofAll(Comparators.naturalComparator(), iterator().collect(partialFunction));
     }
 
@@ -386,7 +375,6 @@ public final BitSet<T> distinct() {
 
     @Override
     public final BitSet<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
@@ -401,19 +389,16 @@ public final BitSet<T> dropUntil(Predicate<? super T> predicate) {
 
     @Override
     public final <U> SortedSet<U> flatMap(Comparator<? super U> comparator, Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(comparator, iterator().flatMap(mapper));
     }
 
     @Override
     public final <U> Set<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? HashSet.empty() : HashSet.ofAll(this).flatMap(mapper);
     }
 
     @Override
     public final <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return iterator().foldRight(zero, f);
     }
 
@@ -476,7 +461,6 @@ public final T last() {
 
     @Override
     public final BitSet<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -490,13 +474,11 @@ public final String stringPrefix() {
 
     @Override
     public final <U> SortedSet<U> map(Comparator<? super U> comparator, Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(comparator, iterator().map(mapper));
     }
 
     @Override
     public final <U> Set<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? HashSet.empty() : HashSet.ofAll(this).map(mapper);
     }
 
@@ -575,7 +557,6 @@ public final Option<BitSet<T>> tailOption() {
 
     @Override
     public final BitSet<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
@@ -596,33 +577,27 @@ public final java.util.SortedSet<T> toJavaSet() {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super BitSet<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
     @Override
     public final BitSet<T> union(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return elements.isEmpty() ? this : addAll(elements);
     }
 
     @Override
     public final <U> TreeSet<Tuple2<T, U>> zip(Iterable<? extends U> that) {
-        Objects.requireNonNull(that, "that is null");
         final Comparator<Tuple2<T, U>> tuple2Comparator = Tuple2.comparator(comparator(), Comparators.naturalComparator());
         return TreeSet.ofAll(tuple2Comparator, iterator().zip(that));
     }
 
     @Override
     public final <U, R> TreeSet<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(Comparators.naturalComparator(), iterator().zipWith(that, mapper));
     }
 
     @Override
     public final <U> TreeSet<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         final Comparator<Tuple2<T, U>> tuple2Comparator = Tuple2.comparator(comparator(), Comparators.naturalComparator());
         return TreeSet.ofAll(tuple2Comparator, iterator().zipAll(that, thisElem, thatElem));
     }
@@ -636,7 +611,6 @@ public final TreeSet<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public final <U> TreeSet<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(Comparators.naturalComparator(), iterator().zipWithIndex(mapper));
     }
 
@@ -711,13 +685,11 @@ BitSet<T> addElement(int element) {
 
         @Override
         public BitSet<T> distinctBy(Comparator<? super T> comparator) {
-            Objects.requireNonNull(comparator, "comparator is null");
             return isEmpty() ? this : createFromAll(iterator().distinctBy(comparator));
         }
 
         @Override
         public <U> BitSet<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-            Objects.requireNonNull(keyExtractor, "keyExtractor is null");
             return isEmpty() ? this : createFromAll(iterator().distinctBy(keyExtractor));
         }
 
@@ -745,14 +717,12 @@ public BitSet<T> dropRight(int n) {
 
         @Override
         public BitSet<T> dropWhile(Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             final BitSet<T> bitSet = createFromAll(iterator().dropWhile(predicate));
             return (bitSet.length() == length()) ? this : bitSet;
         }
 
         @Override
         public BitSet<T> intersect(Set<? extends T> elements) {
-            Objects.requireNonNull(elements, "elements is null");
             if (isEmpty()) {
                 return this;
             } else if (elements.isEmpty()) {
@@ -806,7 +776,6 @@ public Iterator<BitSet<T>> sliding(int size, int step) {
 
         @Override
         public Tuple2<BitSet<T>, BitSet<T>> span(Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             return iterator().span(predicate).map(this::createFromAll, this::createFromAll);
         }
 
@@ -822,14 +791,12 @@ public Tuple2<BitSet<T>, BitSet<T>> partition(Predicate<? super T> predicate) {
 
         @Override
         public BitSet<T> filter(Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             final BitSet<T> bitSet = createFromAll(iterator().filter(predicate));
             return (bitSet.length() == length()) ? this : bitSet;
         }
 
         @Override
         public BitSet<T> filterNot(Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             final BitSet<T> bitSet = createFromAll(iterator().filterNot(predicate));
             return (bitSet.length() == length()) ? this : bitSet;
         }
@@ -846,7 +813,6 @@ public Comparator<T> comparator() {
 
         @Override
         public BitSet<T> takeWhile(Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             final BitSet<T> result = createFromAll(iterator().takeWhile(predicate));
             return (result.length() == length()) ? this : result;
         }
diff --git a/src/main/java/io/vavr/collection/CharSeq.java b/src/main/java/io/vavr/collection/CharSeq.java
index 0730a3e52..bb9be83dd 100644
--- a/src/main/java/io/vavr/collection/CharSeq.java
+++ b/src/main/java/io/vavr/collection/CharSeq.java
@@ -86,7 +86,6 @@ public static Collector<Character, ArrayList<Character>, CharSeq> collector() {
      */
     // DEV-NOTE: Needs to be 'of' instead of 'ofAll' because 'ofAll(CharSeq)' is ambiguous.
     public static CharSeq of(CharSequence sequence) {
-        Objects.requireNonNull(sequence, "sequence is null");
         if (sequence instanceof CharSeq) {
             return (CharSeq) sequence;
         } else {
@@ -112,7 +111,6 @@ public static CharSeq of(char character) {
      * @throws NullPointerException if {@code elements} is null
      */
     public static CharSeq of(char... characters) {
-        Objects.requireNonNull(characters, "characters is null");
         if (characters.length == 0) {
             return empty();
         } else {
@@ -134,7 +132,6 @@ public static CharSeq of(char... characters) {
      */
     @SuppressWarnings("unchecked")
     public static CharSeq ofAll(Iterable<? extends Character> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (Collections.isEmpty(elements)){
             return EMPTY;
         }
@@ -162,7 +159,6 @@ public static CharSeq ofAll(Iterable<? extends Character> elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static CharSeq tabulate(int n, Function<? super Integer, ? extends Character> f) {
-        Objects.requireNonNull(f, "f is null");
         final StringBuilder sb = new StringBuilder();
         for (int i = 0; i < n; i++) {
             sb.append(f.apply(i).charValue());
@@ -398,7 +394,6 @@ public CharSeq append(Character element) {
 
     @Override
     public CharSeq appendAll(Iterable<? extends Character> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (Collections.isEmpty(elements)) {
             return this;
         }
@@ -456,14 +451,12 @@ public CharSeq distinct() {
 
     @Override
     public CharSeq distinctBy(Comparator<? super Character> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final java.util.Set<Character> seen = new java.util.TreeSet<>(comparator);
         return filter(seen::add);
     }
 
     @Override
     public <U> CharSeq distinctBy(Function<? super Character, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         final java.util.Set<U> seen = new java.util.HashSet<>();
         return filter(t -> seen.add(keyExtractor.apply(t)));
     }
@@ -486,7 +479,6 @@ public CharSeq dropUntil(Predicate<? super Character> predicate) {
 
     @Override
     public CharSeq dropWhile(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropUntil(predicate.negate());
     }
 
@@ -503,7 +495,6 @@ public CharSeq dropRight(int n) {
 
     @Override
     public CharSeq dropRightWhile(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
@@ -514,7 +505,6 @@ public CharSeq dropRightUntil(Predicate<? super Character> predicate) {
 
     @Override
     public CharSeq filter(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final StringBuilder sb = new StringBuilder();
         for (int i = 0; i < back.length(); i++) {
             final char ch = get(i);
@@ -533,13 +523,11 @@ public CharSeq filter(Predicate<? super Character> predicate) {
 
     @Override
     public CharSeq filterNot(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Collections.filterNot(this, predicate);
     }
 
     @Override
     public <U> IndexedSeq<U> flatMap(Function<? super Character, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return Vector.empty();
         } else {
@@ -554,7 +542,6 @@ public <U> IndexedSeq<U> flatMap(Function<? super Character, ? extends Iterable<
     }
 
     public CharSeq flatMapChars(CharFunction<? extends CharSequence> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -614,7 +601,6 @@ public CharSeq insert(int index, Character element) {
 
     @Override
     public CharSeq insertAll(int index, Iterable<? extends Character> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (index < 0) {
             throw new IndexOutOfBoundsException("insertAll(" + index + ", elements)");
         }
@@ -650,7 +636,6 @@ public CharSeq intersperse(Character element) {
 
     @Override
     public <U> IndexedSeq<U> map(Function<? super Character, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         IndexedSeq<U> result = Vector.empty();
         for (int i = 0; i < length(); i++) {
             result = result.append(mapper.apply(get(i)));
@@ -717,7 +702,6 @@ public CharSeq patch(int from, Iterable<? extends Character> that, int replaced)
     }
 
     public CharSeq mapChars(CharUnaryOperator mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -731,7 +715,6 @@ public CharSeq mapChars(CharUnaryOperator mapper) {
 
     @Override
     public Tuple2<CharSeq, CharSeq> partition(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Tuple.of(EMPTY, EMPTY);
         }
@@ -752,7 +735,6 @@ public Tuple2<CharSeq, CharSeq> partition(Predicate<? super Character> predicate
 
     @Override
     public CharSeq peek(Consumer<? super Character> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(get(0));
         }
@@ -786,7 +768,6 @@ public CharSeq prepend(Character element) {
 
     @Override
     public CharSeq prependAll(Iterable<? extends Character> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (Collections.isEmpty(elements)) {
             return this;
         } else if (isEmpty()) {
@@ -821,7 +802,6 @@ public CharSeq remove(Character element) {
 
     @Override
     public CharSeq removeFirst(Predicate<Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final StringBuilder sb = new StringBuilder();
         boolean found = false;
         for (int i = 0; i < back.length(); i++) {
@@ -840,7 +820,6 @@ public CharSeq removeFirst(Predicate<Character> predicate) {
 
     @Override
     public CharSeq removeLast(Predicate<Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = length() - 1; i >= 0; i--) {
             if (predicate.test(get(i))) {
                 return removeAt(i);
@@ -990,7 +969,6 @@ public CharSeq sorted() {
 
     @Override
     public CharSeq sorted(Comparator<? super Character> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : toJavaStream().sorted(comparator).collect(CharSeq.collector());
     }
 
@@ -1006,7 +984,6 @@ public <U> CharSeq sortBy(Comparator<? super U> comparator, Function<? super Cha
 
     @Override
     public Tuple2<CharSeq, CharSeq> span(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final StringBuilder sb = new StringBuilder();
         for (int i = 0; i < length(); i++) {
             final char c = get(i);
@@ -1065,7 +1042,6 @@ public CharSeq takeUntil(Predicate<? super Character> predicate) {
 
     @Override
     public CharSeq takeWhile(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeUntil(predicate.negate());
     }
 
@@ -1087,7 +1063,6 @@ public CharSeq takeRightUntil(Predicate<? super Character> predicate) {
 
     @Override
     public CharSeq takeRightWhile(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightUntil(predicate.negate());
     }
 
@@ -1100,7 +1075,6 @@ public CharSeq takeRightWhile(Predicate<? super Character> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super CharSeq, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1116,7 +1090,6 @@ public CharSeq update(int index, Character element) {
 
     @Override
     public CharSeq update(int index, Function<? super Character, ? extends Character> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         final char c = updater.apply(get(index));
         return update(index, c);
     }
@@ -1128,8 +1101,6 @@ public <U> IndexedSeq<Tuple2<Character, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> IndexedSeq<R> zipWith(Iterable<? extends U> that, BiFunction<? super Character, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         IndexedSeq<R> result = Vector.empty();
         final io.vavr.collection.Iterator<Character> list1 = iterator();
         final java.util.Iterator<? extends U> list2 = that.iterator();
@@ -1141,7 +1112,6 @@ public <U, R> IndexedSeq<R> zipWith(Iterable<? extends U> that, BiFunction<? sup
 
     @Override
     public <U> IndexedSeq<Tuple2<Character, U>> zipAll(Iterable<? extends U> that, Character thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         IndexedSeq<Tuple2<Character, U>> result = Vector.empty();
         final io.vavr.collection.Iterator<Character> list1 = iterator();
         final java.util.Iterator<? extends U> list2 = that.iterator();
@@ -1160,7 +1130,6 @@ public IndexedSeq<Tuple2<Character, Integer>> zipWithIndex() {
 
     @Override
     public <U> IndexedSeq<U> zipWithIndex(BiFunction<? super Character, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         IndexedSeq<U> result = Vector.empty();
         for (int i = 0; i < length(); i++) {
             result = result.append(mapper.apply(get(i), i));
@@ -1196,7 +1165,6 @@ public Tuple2<CharSeq, CharSeq> splitAt(int n) {
 
     @Override
     public Tuple2<CharSeq, CharSeq> splitAt(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Tuple.of(EMPTY, EMPTY);
         }
@@ -1214,7 +1182,6 @@ public Tuple2<CharSeq, CharSeq> splitAt(Predicate<? super Character> predicate)
 
     @Override
     public Tuple2<CharSeq, CharSeq> splitAtInclusive(Predicate<? super Character> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Tuple.of(EMPTY, EMPTY);
         }
diff --git a/src/main/java/io/vavr/collection/Collections.java b/src/main/java/io/vavr/collection/Collections.java
index 74fdefcb4..dc724f07f 100644
--- a/src/main/java/io/vavr/collection/Collections.java
+++ b/src/main/java/io/vavr/collection/Collections.java
@@ -54,7 +54,6 @@ static boolean areEqual(Iterable<?> iterable1, Iterable<?> iterable2) {
     }
 
     static <T, C extends Seq<T>> C asJava(C source, Consumer<? super java.util.List<T>> action, ChangePolicy changePolicy) {
-        Objects.requireNonNull(action, "action is null");
         final ListView<T, C> view = JavaConverters.asJava(source, changePolicy);
         action.accept(view);
         return view.getDelegate();
@@ -75,7 +74,6 @@ static <T, S extends Seq<T>> Iterator<S> crossProduct(S empty, S seq, int power)
     // see https://github.com/vavr-io/vavr/issues/2007
     @SuppressWarnings("unchecked")
     static <T, S extends IndexedSeq<T>> S dropRightUntil(S seq, Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = seq.length() - 1; i >= 0; i--) {
             if (predicate.test(seq.get(i))) {
                 return (S) seq.take(i + 1);
@@ -89,7 +87,6 @@ static <T, S extends IndexedSeq<T>> S dropRightUntil(S seq, Predicate<? super T>
     // see https://github.com/vavr-io/vavr/issues/2007
     @SuppressWarnings("unchecked")
     static <T, S extends IndexedSeq<T>> S dropUntil(S seq, Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = 0; i < seq.length(); i++) {
             if (predicate.test(seq.get(i))) {
                 return (S) seq.drop(i);
@@ -171,7 +168,6 @@ static <V> boolean equals(Set<V> source, Object object) {
     }
 
     static <T> Iterator<T> fill(int n, Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return tabulate(n, ignored -> supplier.get());
     }
 
@@ -190,15 +186,10 @@ static <T> Iterator<T> fillObject(int n, T element) {
     }
 
     static <C extends Traversable<T>, T> C fill(int n, Supplier<? extends T> s, C empty, Function<T[], C> of) {
-        Objects.requireNonNull(s, "s is null");
-        Objects.requireNonNull(empty, "empty is null");
-        Objects.requireNonNull(of, "of is null");
         return tabulate(n, anything -> s.get(), empty, of);
     }
 
     static <C extends Traversable<T>, T> C fillObject(int n, T element, C empty, Function<T[], C> of) {
-        Objects.requireNonNull(empty, "empty is null");
-        Objects.requireNonNull(of, "of is null");
         if (n <= 0) {
             return empty;
         } else {
@@ -211,7 +202,6 @@ static <C extends Traversable<T>, T> C fillObject(int n, T element, C empty, Fun
 
     @SuppressWarnings("unchecked")
     static <C extends Traversable<T>, T> C filterNot(C source, Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (source.isEmpty()) {
             return source;
         } else {
@@ -227,8 +217,6 @@ static <T, S extends Seq<T>> Seq<S> group(S source, Supplier<S> supplier) {
     }
 
     static <T, C, R extends Iterable<T>> Map<C, R> groupBy(Traversable<T> source, Function<? super T, ? extends C> classifier, Function<? super Iterable<T>, R> mapper) {
-        Objects.requireNonNull(classifier, "classifier is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         Map<C, R> results = LinkedHashMap.empty();
         for (java.util.Map.Entry<? extends C, Collection<T>> entry : groupBy(source, classifier)) {
             results = results.put(entry.getKey(), mapper.apply(entry.getValue()));
@@ -299,9 +287,6 @@ static <T> T last(Traversable<T> source){
 
     @SuppressWarnings("unchecked")
     static <K, V, K2, U extends Map<K2, V>> U mapKeys(Map<K, V> source, U zero, Function<? super K, ? extends K2> keyMapper, BiFunction<? super V, ? super V, ? extends V> valueMerge) {
-        Objects.requireNonNull(zero, "zero is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMerge, "valueMerge is null");
         return source.foldLeft(zero, (acc, entry) -> {
             final K2 k2 = keyMapper.apply(entry._1);
             final V v2 = entry._2;
@@ -313,7 +298,6 @@ static <K, V, K2, U extends Map<K2, V>> U mapKeys(Map<K, V> source, U zero, Func
 
     static <C extends Traversable<T>, T> Tuple2<C, C> partition(C collection, Function<Iterable<T>, C> creator,
                                                                 Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final java.util.List<T> left = new java.util.ArrayList<>();
         final java.util.List<T> right = new java.util.ArrayList<>();
         for (T element : collection) {
@@ -324,7 +308,6 @@ static <C extends Traversable<T>, T> Tuple2<C, C> partition(C collection, Functi
 
     @SuppressWarnings("unchecked")
     static <C extends Traversable<T>, T> C removeAll(C source, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (source.isEmpty()) {
             return source;
         } else {
@@ -344,7 +327,6 @@ static <C extends Traversable<T>, T> C removeAll(C source, T element) {
 
     @SuppressWarnings("unchecked")
     static <C extends Traversable<T>, T> C retainAll(C source, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (source.isEmpty()) {
             return source;
         } else {
@@ -415,21 +397,17 @@ static <T, C extends Seq<T>> C rotateRight(C source, int n) {
 
     static <T, U, R extends Traversable<U>> R scanLeft(Traversable<? extends T> source,
                                                        U zero, BiFunction<? super U, ? super T, ? extends U> operation, Function<Iterator<U>, R> finisher) {
-        Objects.requireNonNull(operation, "operation is null");
         final Iterator<U> iterator = source.iterator().scanLeft(zero, operation);
         return finisher.apply(iterator);
     }
 
     static <T, U, R extends Traversable<U>> R scanRight(Traversable<? extends T> source,
                                                         U zero, BiFunction<? super T, ? super U, ? extends U> operation, Function<Iterator<U>, R> finisher) {
-        Objects.requireNonNull(operation, "operation is null");
         final Iterator<? extends T> reversedElements = reverseIterator(source);
         return scanLeft(reversedElements, zero, (u, t) -> operation.apply(t, u), us -> finisher.apply(reverseIterator(us)));
     }
 
     static <T, U, R extends Seq<T>> R sortBy(Seq<? extends T> source, Comparator<? super U> comparator, Function<? super T, ? extends U> mapper, Collector<T, ?, R> collector) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return source.toJavaStream()
                 .sorted((e1, e2) -> comparator.compare(mapper.apply(e1), mapper.apply(e2)))
                 .collect(collector);
@@ -464,7 +442,6 @@ static void subSequenceRangeCheck(int beginIndex, int endIndex, int length) {
     }
 
     static <T> Iterator<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         if (n <= 0) {
             return Iterator.empty();
         } else {
@@ -489,9 +466,6 @@ public T next() {
     }
 
     static <C extends Traversable<T>, T> C tabulate(int n, Function<? super Integer, ? extends T> f, C empty, Function<T[], C> of) {
-        Objects.requireNonNull(f, "f is null");
-        Objects.requireNonNull(empty, "empty is null");
-        Objects.requireNonNull(of, "of is null");
         if (n <= 0) {
             return empty;
         } else {
@@ -509,7 +483,6 @@ static <C extends Traversable<T>, T> C tabulate(int n, Function<? super Integer,
     // see https://github.com/vavr-io/vavr/issues/2007
     @SuppressWarnings("unchecked")
     static <T, S extends IndexedSeq<T>> S takeRightUntil(S seq, Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = seq.length() - 1; i >= 0; i--) {
             if (predicate.test(seq.get(i))) {
                 return (S) seq.drop(i + 1);
@@ -523,7 +496,6 @@ static <T, S extends IndexedSeq<T>> S takeRightUntil(S seq, Predicate<? super T>
     // see https://github.com/vavr-io/vavr/issues/2007
     @SuppressWarnings("unchecked")
     static <T, S extends IndexedSeq<T>> S takeUntil(S seq, Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = 0; i < seq.length(); i++) {
             if (predicate.test(seq.get(i))) {
                 return (S) seq.take(i);
@@ -533,7 +505,6 @@ static <T, S extends IndexedSeq<T>> S takeUntil(S seq, Predicate<? super T> pred
     }
 
     static <T, U extends Seq<T>, V extends Seq<U>> V transpose(V matrix, Function<Iterable<U>, V> rowFactory, Function<T[], U> columnFactory) {
-        Objects.requireNonNull(matrix, "matrix is null");
         if (matrix.isEmpty() || (matrix.length() == 1 && matrix.head().length() <= 1)) {
             return matrix;
         } else {
diff --git a/src/main/java/io/vavr/collection/Foldable.java b/src/main/java/io/vavr/collection/Foldable.java
index 91fcf5cd4..bd23d23fc 100644
--- a/src/main/java/io/vavr/collection/Foldable.java
+++ b/src/main/java/io/vavr/collection/Foldable.java
@@ -83,7 +83,6 @@ public interface Foldable<T> {
      * @throws NullPointerException if {@code combine} is null
      */
     default T fold(T zero, BiFunction<? super T, ? super T, ? extends T> combine) {
-        Objects.requireNonNull(combine, "combine is null");
         return foldLeft(zero, combine);
     }
 
@@ -133,7 +132,6 @@ default T fold(T zero, BiFunction<? super T, ? super T, ? extends T> combine) {
      * @throws NullPointerException   if {@code op} is null
      */
     default T reduce(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return reduceLeft(op);
     }
 
@@ -146,7 +144,6 @@ default T reduce(BiFunction<? super T, ? super T, ? extends T> op) {
      * @throws NullPointerException if {@code op} is null
      */
     default Option<T> reduceOption(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return reduceLeftOption(op);
     }
 
diff --git a/src/main/java/io/vavr/collection/HashMap.java b/src/main/java/io/vavr/collection/HashMap.java
index 5f5dc4861..fa9b4056e 100644
--- a/src/main/java/io/vavr/collection/HashMap.java
+++ b/src/main/java/io/vavr/collection/HashMap.java
@@ -77,7 +77,6 @@ public static <K, V> Collector<Tuple2<K, V>, ArrayList<Tuple2<K, V>>, HashMap<K,
      * @return A {@link HashMap} Collector.
      */
     public static <K, V, T extends V> Collector<T, ArrayList<T>, HashMap<K, V>> collector(Function<? super T, ? extends K> keyMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return HashMap.collector(keyMapper, v -> v);
     }
 
@@ -94,8 +93,6 @@ public static <K, V, T extends V> Collector<T, ArrayList<T>, HashMap<K, V>> coll
      */
     public static <K, V, T> Collector<T, ArrayList<T>, HashMap<K, V>> collector(
             Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return Collections.toListAndThen(arr -> HashMap.ofEntries(Iterator.ofAll(arr)
                 .map(t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)))));
     }
@@ -141,7 +138,6 @@ public static <K, V> HashMap<K, V> of(Tuple2<? extends K, ? extends V> entry) {
      * @return A new Map containing the given map
      */
     public static <K, V> HashMap<K, V> ofAll(java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         HashArrayMappedTrie<K, V> tree = HashArrayMappedTrie.empty();
         for (java.util.Map.Entry<? extends K, ? extends V> entry : map.entrySet()) {
             tree = tree.put(entry.getKey(), entry.getValue());
@@ -414,7 +410,6 @@ public static <K, V> HashMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3, K k4,
      */
     @SuppressWarnings("unchecked")
     public static <K, V> HashMap<K, V> tabulate(int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         return ofEntries(Collections.tabulate(n, (Function<? super Integer, ? extends Tuple2<K, V>>) f));
     }
 
@@ -430,7 +425,6 @@ public static <K, V> HashMap<K, V> tabulate(int n, Function<? super Integer, ? e
      */
     @SuppressWarnings("unchecked")
     public static <K, V> HashMap<K, V> fill(int n, Supplier<? extends Tuple2<? extends K, ? extends V>> s) {
-        Objects.requireNonNull(s, "s is null");
         return ofEntries(Collections.fill(n, (Supplier<? extends Tuple2<K, V>>) s));
     }
 
@@ -444,7 +438,6 @@ public static <K, V> HashMap<K, V> fill(int n, Supplier<? extends Tuple2<? exten
      */
     @SafeVarargs
     public static <K, V> HashMap<K, V> ofEntries(java.util.Map.Entry<? extends K, ? extends V>... entries) {
-        Objects.requireNonNull(entries, "entries is null");
         HashArrayMappedTrie<K, V> trie = HashArrayMappedTrie.empty();
         for (java.util.Map.Entry<? extends K, ? extends V> entry : entries) {
             trie = trie.put(entry.getKey(), entry.getValue());
@@ -462,7 +455,6 @@ public static <K, V> HashMap<K, V> ofEntries(java.util.Map.Entry<? extends K, ?
      */
     @SafeVarargs
     public static <K, V> HashMap<K, V> ofEntries(Tuple2<? extends K, ? extends V>... entries) {
-        Objects.requireNonNull(entries, "entries is null");
         HashArrayMappedTrie<K, V> trie = HashArrayMappedTrie.empty();
         for (Tuple2<? extends K, ? extends V> entry : entries) {
             trie = trie.put(entry._1, entry._2);
@@ -480,7 +472,6 @@ public static <K, V> HashMap<K, V> ofEntries(Tuple2<? extends K, ? extends V>...
      */
     @SuppressWarnings("unchecked")
     public static <K, V> HashMap<K, V> ofEntries(Iterable<? extends Tuple2<? extends K, ? extends V>> entries) {
-        Objects.requireNonNull(entries, "entries is null");
         if (entries instanceof HashMap) {
             return (HashMap<K, V>) entries;
         } else {
@@ -494,8 +485,6 @@ public static <K, V> HashMap<K, V> ofEntries(Iterable<? extends Tuple2<? extends
 
     @Override
     public <K2, V2> HashMap<K2, V2> bimap(Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         final Iterator<Tuple2<K2, V2>> entries = iterator().map(entry -> Tuple.of(keyMapper.apply(entry._1), valueMapper.apply(entry._2)));
         return HashMap.ofEntries(entries);
     }
@@ -592,7 +581,6 @@ public HashMap<K, V> filterNotValues(Predicate<? super V> predicate) {
 
     @Override
     public <K2, V2> HashMap<K2, V2> flatMap(BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2, V2>>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(HashMap.<K2, V2> empty(), (acc, entry) -> {
             for (Tuple2<? extends K2, ? extends V2> mappedEntry : mapper.apply(entry._1, entry._2)) {
                 acc = acc.put(mappedEntry);
@@ -691,13 +679,11 @@ public Tuple2<K, V> last() {
 
     @Override
     public <K2, V2> HashMap<K2, V2> map(BiFunction<? super K, ? super V, Tuple2<K2, V2>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(HashMap.empty(), (acc, entry) -> acc.put(entry.map(mapper)));
     }
 
     @Override
     public <K2> HashMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return map((k, v) -> Tuple.of(keyMapper.apply(k), v));
     }
 
@@ -708,7 +694,6 @@ public <K2> HashMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMapper,
 
     @Override
     public <V2> HashMap<K, V2> mapValues(Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return map((k, v) -> Tuple.of(k, valueMapper.apply(v)));
     }
 
@@ -772,7 +757,6 @@ public HashMap<K, V> remove(K key) {
 
     @Override
     public HashMap<K, V> removeAll(Iterable<? extends K> keys) {
-        Objects.requireNonNull(keys, "keys is null");
         HashArrayMappedTrie<K, V> result = trie;
         for (K key : keys) {
             result = result.remove(key);
@@ -814,7 +798,6 @@ public HashMap<K, V> replaceAll(BiFunction<? super K, ? super V, ? extends V> fu
 
     @Override
     public HashMap<K, V> retainAll(Iterable<? extends Tuple2<K, V>> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         HashArrayMappedTrie<K, V> tree = HashArrayMappedTrie.empty();
         for (Tuple2<K, V> entry : elements) {
             if (contains(entry)) {
diff --git a/src/main/java/io/vavr/collection/HashMultimap.java b/src/main/java/io/vavr/collection/HashMultimap.java
index 44fd3a810..6a27d5ef7 100644
--- a/src/main/java/io/vavr/collection/HashMultimap.java
+++ b/src/main/java/io/vavr/collection/HashMultimap.java
@@ -96,7 +96,6 @@ public <K, V2 extends V> HashMultimap<K, V2> empty() {
          * @return A new HashMultimap containing the given entries.
          */
         public <K, V2 extends V> HashMultimap<K, V2> ofEntries(Iterable<? extends Tuple2<? extends K, ? extends V2>> entries) {
-            Objects.requireNonNull(entries, "entries is null");
             HashMultimap<K, V2> result = empty();
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -114,7 +113,6 @@ public <K, V2 extends V> HashMultimap<K, V2> ofEntries(Iterable<? extends Tuple2
          */
         @SafeVarargs
         public final <K, V2 extends V> HashMultimap<K, V2> ofEntries(Tuple2<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(entries, "entries is null");
             HashMultimap<K, V2> result = empty();
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -132,7 +130,6 @@ public final <K, V2 extends V> HashMultimap<K, V2> ofEntries(Tuple2<? extends K,
          */
         @SafeVarargs
         public final <K, V2 extends V> HashMultimap<K, V2> ofEntries(java.util.Map.Entry<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(entries, "entries is null");
             HashMultimap<K, V2> result = empty();
             for (java.util.Map.Entry<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry.getKey(), entry.getValue());
@@ -197,7 +194,6 @@ public <T, K, V2 extends V> HashMultimap<K, V2> ofAll(java.util.stream.Stream<?
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> HashMultimap<K, V2> tabulate(int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V2>> f) {
-            Objects.requireNonNull(f, "f is null");
             return ofEntries(Collections.tabulate(n, (Function<? super Integer, ? extends Tuple2<K, V2>>) f));
         }
 
@@ -213,7 +209,6 @@ public <K, V2 extends V> HashMultimap<K, V2> tabulate(int n, Function<? super In
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> HashMultimap<K, V2> fill(int n, Supplier<? extends Tuple2<? extends K, ? extends V2>> s) {
-            Objects.requireNonNull(s, "s is null");
             return ofEntries(Collections.fill(n, (Supplier<? extends Tuple2<K, V2>>) s));
         }
 
diff --git a/src/main/java/io/vavr/collection/HashSet.java b/src/main/java/io/vavr/collection/HashSet.java
index b7f678ad9..0c0b30e3f 100644
--- a/src/main/java/io/vavr/collection/HashSet.java
+++ b/src/main/java/io/vavr/collection/HashSet.java
@@ -108,7 +108,6 @@ public static <T> HashSet<T> of(T element) {
      */
     @SafeVarargs
     public static <T> HashSet<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         HashArrayMappedTrie<T, T> tree = HashArrayMappedTrie.empty();
         for (T element : elements) {
             tree = tree.put(element, element);
@@ -127,7 +126,6 @@ public static <T> HashSet<T> of(T... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> HashSet<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return Collections.tabulate(n, f, HashSet.empty(), HashSet::of);
     }
 
@@ -141,7 +139,6 @@ public static <T> HashSet<T> tabulate(int n, Function<? super Integer, ? extends
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> HashSet<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return Collections.fill(n, s, HashSet.empty(), HashSet::of);
     }
 
@@ -154,7 +151,6 @@ public static <T> HashSet<T> fill(int n, Supplier<? extends T> s) {
      */
     @SuppressWarnings("unchecked")
     public static <T> HashSet<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof HashSet) {
             return (HashSet<T>) elements;
         } else {
@@ -171,7 +167,6 @@ public static <T> HashSet<T> ofAll(Iterable<? extends T> elements) {
      * @return A HashSet containing the given elements in the same order.
      */
     public static <T> HashSet<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return HashSet.ofAll(Iterator.ofAll(javaStream.iterator()));
     }
 
@@ -183,7 +178,6 @@ public static <T> HashSet<T> ofAll(java.util.stream.Stream<? extends T> javaStre
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -195,7 +189,6 @@ public static HashSet<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -207,7 +200,6 @@ public static HashSet<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -219,7 +211,6 @@ public static HashSet<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -231,7 +222,6 @@ public static HashSet<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -243,7 +233,6 @@ public static HashSet<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -255,7 +244,6 @@ public static HashSet<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -267,7 +255,6 @@ public static HashSet<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static HashSet<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return HashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -486,7 +473,6 @@ public HashSet<T> add(T element) {
 
     @Override
     public HashSet<T> addAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() && elements instanceof HashSet) {
             @SuppressWarnings("unchecked")
             final HashSet<T> set = (HashSet<T>) elements;
@@ -512,7 +498,6 @@ public boolean contains(T element) {
 
     @Override
     public HashSet<T> diff(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() || elements.isEmpty()) {
             return this;
         } else {
@@ -527,13 +512,11 @@ public HashSet<T> distinct() {
 
     @Override
     public HashSet<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return HashSet.ofAll(iterator().distinctBy(comparator));
     }
 
     @Override
     public <U> HashSet<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return HashSet.ofAll(iterator().distinctBy(keyExtractor));
     }
 
@@ -553,20 +536,17 @@ public HashSet<T> dropRight(int n) {
 
     @Override
     public HashSet<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public HashSet<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final HashSet<T> dropped = HashSet.ofAll(iterator().dropWhile(predicate));
         return dropped.length() == length() ? this : dropped;
     }
 
     @Override
     public HashSet<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final HashSet<T> filtered = HashSet.ofAll(iterator().filter(predicate));
 
         if (filtered.isEmpty()) {
@@ -580,13 +560,11 @@ public HashSet<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public HashSet<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
     @Override
     public <U> HashSet<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -641,7 +619,6 @@ public Option<HashSet<T>> initOption() {
 
     @Override
     public HashSet<T> intersect(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() || elements.isEmpty()) {
             return empty();
         } else {
@@ -702,7 +679,6 @@ public int length() {
 
     @Override
     public <U> HashSet<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -736,7 +712,6 @@ public Tuple2<HashSet<T>, HashSet<T>> partition(Predicate<? super T> predicate)
 
     @Override
     public HashSet<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(iterator().head());
         }
@@ -805,7 +780,6 @@ public Iterator<HashSet<T>> sliding(int size, int step) {
 
     @Override
     public Tuple2<HashSet<T>, HashSet<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Tuple2<Iterator<T>, Iterator<T>> t = iterator().span(predicate);
         return Tuple.of(HashSet.ofAll(t._1), HashSet.ofAll(t._2));
     }
@@ -845,13 +819,11 @@ public HashSet<T> takeRight(int n) {
 
     @Override
     public HashSet<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @Override
     public HashSet<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final HashSet<T> taken = HashSet.ofAll(iterator().takeWhile(predicate));
         return taken.length() == length() ? this : taken;
     }
@@ -865,7 +837,6 @@ public HashSet<T> takeWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super HashSet<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -877,7 +848,6 @@ public java.util.HashSet<T> toJavaSet() {
     @SuppressWarnings("unchecked")
     @Override
     public HashSet<T> union(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty()) {
             if (elements instanceof HashSet) {
                 return (HashSet<T>) elements;
@@ -903,14 +873,11 @@ public <U> HashSet<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> HashSet<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return HashSet.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> HashSet<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return HashSet.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -921,7 +888,6 @@ public HashSet<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> HashSet<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return HashSet.ofAll(iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/IndexedSeq.java b/src/main/java/io/vavr/collection/IndexedSeq.java
index 1c266510c..2a263cfaa 100644
--- a/src/main/java/io/vavr/collection/IndexedSeq.java
+++ b/src/main/java/io/vavr/collection/IndexedSeq.java
@@ -130,7 +130,6 @@ public boolean isDefinedAt(Integer index) {
 
     @Override
     default boolean endsWith(Seq<? extends T> that) {
-        Objects.requireNonNull(that, "that is null");
         if (that instanceof IndexedSeq) {
             int i = length() - 1;
             int j = that.length() - 1;
@@ -171,7 +170,6 @@ default boolean endsWith(Seq<? extends T> that) {
 
     @Override
     default int indexWhere(Predicate<? super T> predicate, int from) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int start = Math.max(from, 0);
         int n = start + segmentLength(predicate.negate(), start);
         return (n >= length()) ? -1 : n;
@@ -179,7 +177,6 @@ default int indexWhere(Predicate<? super T> predicate, int from) {
 
     @Override
     default int indexOfSlice(Iterable<? extends T> that, int from) {
-        Objects.requireNonNull(that, "that is null");
         return IndexedSeqModule.Slice.indexOfSlice(this, that, from);
     }
 
@@ -215,13 +212,11 @@ default T last() {
 
     @Override
     default int lastIndexOfSlice(Iterable<? extends T> that, int end) {
-        Objects.requireNonNull(that, "that is null");
         return IndexedSeqModule.Slice.lastIndexOfSlice(this, that, end);
     }
 
     @Override
     default int lastIndexWhere(Predicate<? super T> predicate, int end) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int i = Math.min(end, length() - 1);
         while (i >= 0 && !predicate.test(this.get(i))) {
             i--;
@@ -326,7 +321,6 @@ public T next() {
 
     @Override
     default int segmentLength(Predicate<? super T> predicate, int from) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int len = length();
         int i = from;
         while (i < len && predicate.test(this.get(i))) {
@@ -370,7 +364,6 @@ default int segmentLength(Predicate<? super T> predicate, int from) {
 
     @Override
     default boolean startsWith(Iterable<? extends T> that, int offset) {
-        Objects.requireNonNull(that, "that is null");
         if (offset < 0) { return false; }
         if (that instanceof IndexedSeq) {
             IndexedSeq<? extends T> thatIndexedSeq = (IndexedSeq<? extends T>) that;
@@ -484,7 +477,6 @@ default int search(T element) {
      */
     @Override
     default int search(T element, Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         IntUnaryOperator comparison = midIndex -> {
             T midVal = get(midIndex);
             return comparator.compare(midVal, element);
diff --git a/src/main/java/io/vavr/collection/Iterator.java b/src/main/java/io/vavr/collection/Iterator.java
index fa2a8d4bd..dfd34d38c 100644
--- a/src/main/java/io/vavr/collection/Iterator.java
+++ b/src/main/java/io/vavr/collection/Iterator.java
@@ -74,7 +74,6 @@ public interface Iterator<T> extends java.util.Iterator<T>, Traversable<T> {
     @SuppressWarnings("varargs")
     @SafeVarargs
     static <T> Iterator<T> concat(Iterable<? extends T>... iterables) {
-        Objects.requireNonNull(iterables, "iterables is null");
         if (iterables.length == 0) {
             return empty();
         } else {
@@ -90,7 +89,6 @@ static <T> Iterator<T> concat(Iterable<? extends T>... iterables) {
      * @return A new {@code io.vavr.collection.Iterator}
      */
     static <T> Iterator<T> concat(Iterable<? extends Iterable<? extends T>> iterables) {
-        Objects.requireNonNull(iterables, "iterables is null");
         final Iterator<Iterator<T>> iterators = ofAll(iterables).map(Iterator::ofAll);
         if (!iterators.hasNext()) {
             return empty();
@@ -154,7 +152,6 @@ static <T> Iterator<T> of(T element) {
     @SafeVarargs
     @SuppressWarnings("varargs")
     static <T> Iterator<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return (elements.length == 0) ? empty() : new ArrayIterator<>(elements);
     }
 
@@ -168,7 +165,6 @@ static <T> Iterator<T> of(T... elements) {
      */
     @SuppressWarnings("unchecked")
     static <T> Iterator<T> ofAll(Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable, "iterable is null");
         if (iterable instanceof Iterator) {
             return (Iterator<T>) iterable;
         } else {
@@ -186,7 +182,6 @@ static <T> Iterator<T> ofAll(Iterable<? extends T> iterable) {
      */
     @SuppressWarnings("unchecked")
     static <T> Iterator<T> ofAll(java.util.Iterator<? extends T> iterator) {
-        Objects.requireNonNull(iterator, "iterator is null");
         if (iterator instanceof Iterator) {
             return (Iterator<T>) iterator;
         } else {
@@ -216,7 +211,6 @@ public T next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Boolean>() {
             int i = 0;
 
@@ -243,7 +237,6 @@ public Boolean next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Byte>() {
             int i = 0;
 
@@ -270,7 +263,6 @@ public Byte next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Character>() {
             int i = 0;
 
@@ -297,7 +289,6 @@ public Character next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Double>() {
             int i = 0;
 
@@ -324,7 +315,6 @@ public Double next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Float>() {
             int i = 0;
 
@@ -351,7 +341,6 @@ public Float next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Integer>() {
             int i = 0;
 
@@ -378,7 +367,6 @@ public Integer next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Long>() {
             int i = 0;
 
@@ -405,7 +393,6 @@ public Long next() {
      * @throws NullPointerException if elements is null
      */
     static Iterator<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return new Iterator<Short>() {
             int i = 0;
 
@@ -435,7 +422,6 @@ public Short next() {
      * @throws NullPointerException if {@code f} is null
      */
     static <T> Iterator<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return io.vavr.collection.Collections.tabulate(n, f);
     }
 
@@ -449,7 +435,6 @@ static <T> Iterator<T> tabulate(int n, Function<? super Integer, ? extends T> f)
      * @throws NullPointerException if {@code s} is null
      */
     static <T> Iterator<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return io.vavr.collection.Collections.fill(n, s);
     }
 
@@ -939,7 +924,6 @@ public Long next() {
      * @return A new {@code Iterator}
      */
     static <T> Iterator<T> continually(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return new Iterator<T>() {
             @Override
             public boolean hasNext() {
@@ -966,7 +950,6 @@ public T next() {
      * @throws NullPointerException if supplier produces null value
      */
     static <T> Iterator<T> iterate(Supplier<? extends Option<? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return new Iterator<T>() {
             Option<? extends T> nextOption;
 
@@ -1000,7 +983,6 @@ public T next() {
      * @return A new {@code Iterator}
      */
     static <T> Iterator<T> iterate(T seed, Function<? super T, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return new Iterator<T>() {
             Function<? super T, ? extends T> nextFunc = s -> {
                 nextFunc = f;
@@ -1051,14 +1033,16 @@ public T next() {
     // -- Additional methods of Iterator
 
     @Override
+    @SuppressWarnings("unchecked")
     default <R> Iterator<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
+        if (!hasNext()) {
+            return (Iterator<R>)this;
+        }
         return filter(partialFunction::isDefinedAt).map(partialFunction);
     }
 
     // DEV-NOTE: cannot use arg Iterable, it would be ambiguous
     default Iterator<T> concat(java.util.Iterator<? extends T> that) {
-        Objects.requireNonNull(that, "that is null");
         if (!that.hasNext()) {
             return this;
         } else if (!hasNext()) {
@@ -1114,7 +1098,6 @@ public T next() {
      * @throws NullPointerException if {@code f} is null
      */
     default <U> U transform(Function<? super Iterator<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1125,8 +1108,6 @@ default <U> Iterator<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     default <U, R> Iterator<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -1151,7 +1132,6 @@ public R next() {
 
     @Override
     default <U> Iterator<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         final java.util.Iterator<? extends U> thatIt = that.iterator();
         if (isEmpty() && !thatIt.hasNext()) {
             return empty();
@@ -1183,7 +1163,6 @@ default Iterator<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     default <U> Iterator<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -1210,8 +1189,6 @@ public U next() {
     @Override
     default <T1, T2> Tuple2<Iterator<T1>, Iterator<T2>> unzip(
             Function<? super T, ? extends T1> unzipper1, Function<? super T, ? extends T2> unzipper2) {
-        Objects.requireNonNull(unzipper1, "unzipper1 is null");
-        Objects.requireNonNull(unzipper2, "unzipper2 is null");
         if (!hasNext()) {
             return Tuple.of(empty(), empty());
         } else {
@@ -1227,9 +1204,6 @@ default <T1, T2, T3> Tuple3<Iterator<T1>, Iterator<T2>, Iterator<T3>> unzip3(
             Function<? super T, ? extends T1> unzipper1,
             Function<? super T, ? extends T2> unzipper2,
             Function<? super T, ? extends T3> unzipper3) {
-        Objects.requireNonNull(unzipper1, "unzipper1 is null");
-        Objects.requireNonNull(unzipper2, "unzipper2 is null");
-        Objects.requireNonNull(unzipper3, "unzipper3 is null");
         if (!hasNext()) {
             return Tuple.of(empty(), empty(), empty());
         } else {
@@ -1295,7 +1269,6 @@ static <T> Iterator<T> unfold(T seed, Function<? super T, Option<Tuple2<? extend
      * @throws NullPointerException if {@code f} is null
      */
     static <T, U> Iterator<U> unfoldLeft(T seed, Function<? super T, Option<Tuple2<? extends T, ? extends U>>> f) {
-        Objects.requireNonNull(f, "f is null");
         return Stream.<U> ofAll(
                 unfoldRight(seed, f.andThen(tupleOpt -> tupleOpt.map(t -> Tuple.of(t._2, t._1)))))
                 .reverse().iterator();
@@ -1327,7 +1300,6 @@ static <T, U> Iterator<U> unfoldLeft(T seed, Function<? super T, Option<Tuple2<?
      * @throws NullPointerException if {@code f} is null
      */
     static <T, U> Iterator<U> unfoldRight(T seed, Function<? super T, Option<Tuple2<? extends U, ? extends T>>> f) {
-        Objects.requireNonNull(f, "the unfold iterating function is null");
         return new Iterator<U>() {
             private Option<Tuple2<? extends U, ? extends T>> nextVal = f.apply(seed);
 
@@ -1361,7 +1333,6 @@ default Iterator<T> distinct() {
 
     @Override
     default Iterator<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1371,7 +1342,6 @@ default Iterator<T> distinctBy(Comparator<? super T> comparator) {
 
     @Override
     default <U> Iterator<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1451,13 +1421,11 @@ public T next() {
 
     @Override
     default Iterator<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     default Iterator<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1477,7 +1445,6 @@ default Iterator<T> dropWhile(Predicate<? super T> predicate) {
      */
     @Override
     default Iterator<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1518,13 +1485,11 @@ public T next() {
      */
     @Override
     default Iterator<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
     @Override
     default Option<T> findLast(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         T last = null;
         while (hasNext()) {
             final T elem = next();
@@ -1545,7 +1510,6 @@ default Option<T> findLast(Predicate<? super T> predicate) {
     // DEV-NOTE: the shorter implementation `concat(map(mapper))` does not perform well
     @Override
     default <U> Iterator<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1577,7 +1541,6 @@ public U next() {
 
     @Override
     default <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return Stream.ofAll(this).foldRight(zero, f);
     }
 
@@ -1682,7 +1645,6 @@ default int length() {
      */
     @Override
     default <U> Iterator<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1730,7 +1692,6 @@ default Iterator<T> orElse(Supplier<? extends Iterable<? extends T>> supplier) {
 
     @Override
     default Tuple2<Iterator<T>, Iterator<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (!hasNext()) {
             return Tuple.of(empty(), empty());
         } else {
@@ -1741,7 +1702,6 @@ default Tuple2<Iterator<T>, Iterator<T>> partition(Predicate<? super T> predicat
 
     @Override
     default Iterator<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1767,7 +1727,6 @@ public T next() {
 
     @Override
     default T reduceLeft(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         if (isEmpty()) {
             throw new NoSuchElementException("reduceLeft on Nil");
         } else {
@@ -1781,7 +1740,6 @@ default T reduceLeft(BiFunction<? super T, ? super T, ? extends T> op) {
 
     @Override
     default T reduceRight(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         if (isEmpty()) {
             throw new NoSuchElementException("reduceRight on Nil");
         } else {
@@ -1862,7 +1820,6 @@ default Traversable<T> scan(T zero, BiFunction<? super T, ? super T, ? extends T
 
     @Override
     default <U> Iterator<U> scanLeft(U zero, BiFunction<? super U, ? super T, ? extends U> operation) {
-        Objects.requireNonNull(operation, "operation is null");
         if (isEmpty()) {
             return of(zero);
         } else {
@@ -1897,7 +1854,6 @@ public U next() {
     // not lazy!
     @Override
     default <U> Iterator<U> scanRight(U zero, BiFunction<? super T, ? super U, ? extends U> operation) {
-        Objects.requireNonNull(operation, "operation is null");
         if (isEmpty()) {
             return of(zero);
         } else {
@@ -1907,7 +1863,6 @@ default <U> Iterator<U> scanRight(U zero, BiFunction<? super T, ? super U, ? ext
 
     @Override
     default Iterator<Seq<T>> slideBy(Function<? super T, ?> classifier) {
-        Objects.requireNonNull(classifier, "classifier is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -1954,7 +1909,6 @@ default Iterator<Seq<T>> sliding(int size, int step) {
 
     @Override
     default Tuple2<Iterator<T>, Iterator<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (!hasNext()) {
             return Tuple.of(empty(), empty());
         } else {
@@ -2057,13 +2011,11 @@ public T next() {
 
     @Override
     default Iterator<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @Override
     default Iterator<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (!hasNext()) {
             return empty();
         } else {
@@ -2139,7 +2091,6 @@ public T next() {
 
     @Override
     public void forEachRemaining(Consumer<? super T> action) {
-        Objects.requireNonNull(action);
         while (index < elements.length) {
             action.accept(elements[index++]);
         }
@@ -2372,7 +2323,6 @@ public Object next() {
 
     @Override
     public void forEachRemaining(Consumer<? super Object> action) {
-        Objects.requireNonNull(action);
     }
 
     @Override
@@ -2483,7 +2433,6 @@ public T next() {
 
     @Override
     public void forEachRemaining(Consumer<? super T> action) {
-        Objects.requireNonNull(action);
         if (hasNext) {
             action.accept(element);
             hasNext = false;
diff --git a/src/main/java/io/vavr/collection/JavaConverters.java b/src/main/java/io/vavr/collection/JavaConverters.java
index 509a0d91b..ee88d1a3c 100644
--- a/src/main/java/io/vavr/collection/JavaConverters.java
+++ b/src/main/java/io/vavr/collection/JavaConverters.java
@@ -130,14 +130,12 @@ public void add(int index, T element) {
         @SuppressWarnings("unchecked")
         @Override
         public boolean addAll(Collection<? extends T> collection) {
-            Objects.requireNonNull(collection, "collection is null");
             return setDelegateAndCheckChanged(() -> (C) getDelegate().appendAll(collection));
         }
 
         @SuppressWarnings("unchecked")
         @Override
         public boolean addAll(int index, Collection<? extends T> collection) {
-            Objects.requireNonNull(collection, "collection is null");
             return setDelegateAndCheckChanged(() -> (C) getDelegate().insertAll(index, collection));
         }
 
@@ -159,7 +157,6 @@ public boolean contains(Object obj) {
 
         @Override
         public boolean containsAll(Collection<?> collection) {
-            Objects.requireNonNull(collection, "collection is null");
             @SuppressWarnings("unchecked") final Collection<T> that = (Collection<T>) collection;
             return getDelegate().containsAll(that);
         }
@@ -217,7 +214,6 @@ public boolean remove(Object obj) {
         @SuppressWarnings("unchecked")
         @Override
         public boolean removeAll(Collection<?> collection) {
-            Objects.requireNonNull(collection, "collection is null");
             @SuppressWarnings("unchecked") final Collection<T> that = (Collection<T>) collection;
             return setDelegateAndCheckChanged(() -> (C) getDelegate().removeAll(that));
         }
@@ -225,7 +221,6 @@ public boolean removeAll(Collection<?> collection) {
         @SuppressWarnings("unchecked")
         @Override
         public boolean retainAll(Collection<?> collection) {
-            Objects.requireNonNull(collection, "collection is null");
             @SuppressWarnings("unchecked") final Collection<T> that = (Collection<T>) collection;
             return setDelegateAndCheckChanged(() -> (C) getDelegate().retainAll(that));
         }
@@ -244,7 +239,6 @@ public int size() {
         @SuppressWarnings("unchecked")
         @Override
         public void sort(Comparator<? super T> comparator) {
-            Objects.requireNonNull(comparator, "comparator is null");
             if (isEmpty()) {
                 return;
             }
@@ -264,7 +258,6 @@ public Object[] toArray() {
         @SuppressWarnings("unchecked")
         @Override
         public <U> U[] toArray(U[] array) {
-            Objects.requireNonNull(array, "array is null");
             final U[] target;
             final C delegate = getDelegate();
             final int length = delegate.length();
@@ -362,7 +355,6 @@ public void remove() {
 
             @Override
             public void forEachRemaining(Consumer<? super T> consumer) {
-                Objects.requireNonNull(consumer, "consumer is  null");
                 checkForComodification();
                 if (nextIndex >= list.size()) {
                     return;
diff --git a/src/main/java/io/vavr/collection/LinearSeq.java b/src/main/java/io/vavr/collection/LinearSeq.java
index 2bd1401ed..1eddd806f 100644
--- a/src/main/java/io/vavr/collection/LinearSeq.java
+++ b/src/main/java/io/vavr/collection/LinearSeq.java
@@ -148,13 +148,11 @@ public boolean isDefinedAt(Integer index) {
 
     @Override
     default int indexOfSlice(Iterable<? extends T> that, int from) {
-        Objects.requireNonNull(that, "that is null");
         return LinearSeqModule.Slice.indexOfSlice(this, that, from);
     }
 
     @Override
     default int indexWhere(Predicate<? super T> predicate, int from) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int i = from;
         LinearSeq<T> these = drop(from);
         while (!these.isEmpty()) {
@@ -184,13 +182,11 @@ default int indexWhere(Predicate<? super T> predicate, int from) {
 
     @Override
     default int lastIndexOfSlice(Iterable<? extends T> that, int end) {
-        Objects.requireNonNull(that, "that is null");
         return LinearSeqModule.Slice.lastIndexOfSlice(this, that, end);
     }
 
     @Override
     default int lastIndexWhere(Predicate<? super T> predicate, int end) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int i = 0;
         LinearSeq<T> these = this;
         int last = -1;
@@ -292,7 +288,6 @@ default Iterator<T> reverseIterator() {
 
     @Override
     default int segmentLength(Predicate<? super T> predicate, int from) {
-        Objects.requireNonNull(predicate, "predicate is null");
         int i = 0;
         LinearSeq<T> these = this.drop(from);
         while (!these.isEmpty() && predicate.test(these.head())) {
@@ -413,7 +408,6 @@ default int search(T element) {
      */
     @Override
     default int search(T element, Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final ToIntFunction<T> comparison = current -> comparator.compare(element, current);
         return LinearSeqModule.Search.linearSearch(this, comparison);
     }
diff --git a/src/main/java/io/vavr/collection/LinkedHashMap.java b/src/main/java/io/vavr/collection/LinkedHashMap.java
index b8121a6ac..1d2ad7a9d 100644
--- a/src/main/java/io/vavr/collection/LinkedHashMap.java
+++ b/src/main/java/io/vavr/collection/LinkedHashMap.java
@@ -76,7 +76,6 @@ public static <K, V> Collector<Tuple2<K, V>, ArrayList<Tuple2<K, V>>, LinkedHash
      * @return A {@link LinkedHashMap} Collector.
      */
     public static <K, V, T extends V> Collector<T, ArrayList<T>, LinkedHashMap<K, V>> collector(Function<? super T, ? extends K> keyMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return LinkedHashMap.collector(keyMapper, v -> v);
     }
 
@@ -93,8 +92,6 @@ public static <K, V, T extends V> Collector<T, ArrayList<T>, LinkedHashMap<K, V>
      */
     public static <K, V, T> Collector<T, ArrayList<T>, LinkedHashMap<K, V>> collector(
             Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return Collections.toListAndThen(arr -> LinkedHashMap.ofEntries(Iterator.ofAll(arr)
           .map(t -> Tuple.of(keyMapper.apply(t), valueMapper.apply(t)))));
     }
@@ -143,7 +140,6 @@ public static <K, V> LinkedHashMap<K, V> of(Tuple2<? extends K, ? extends V> ent
      * @return A new Map containing the given map
      */
     public static <K, V> LinkedHashMap<K, V> ofAll(java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         LinkedHashMap<K, V> result = LinkedHashMap.empty();
         for (java.util.Map.Entry<? extends K, ? extends V> entry : map.entrySet()) {
             result = result.put(entry.getKey(), entry.getValue());
@@ -436,7 +432,6 @@ public static <K, V> LinkedHashMap<K, V> of(K k1, V v1, K k2, V v2, K k3, V v3,
      */
     @SuppressWarnings("unchecked")
     public static <K, V> LinkedHashMap<K, V> tabulate(int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         return ofEntries(Collections.tabulate(n, (Function<? super Integer, ? extends Tuple2<K, V>>) f));
     }
 
@@ -452,7 +447,6 @@ public static <K, V> LinkedHashMap<K, V> tabulate(int n, Function<? super Intege
      */
     @SuppressWarnings("unchecked")
     public static <K, V> LinkedHashMap<K, V> fill(int n, Supplier<? extends Tuple2<? extends K, ? extends V>> s) {
-        Objects.requireNonNull(s, "s is null");
         return ofEntries(Collections.fill(n, (Supplier<? extends Tuple2<K, V>>) s));
     }
 
@@ -501,7 +495,6 @@ public static <K, V> LinkedHashMap<K, V> ofEntries(Tuple2<? extends K, ? extends
      */
     @SuppressWarnings("unchecked")
     public static <K, V> LinkedHashMap<K, V> ofEntries(Iterable<? extends Tuple2<? extends K, ? extends V>> entries) {
-        Objects.requireNonNull(entries, "entries is null");
         if (entries instanceof LinkedHashMap) {
             return (LinkedHashMap<K, V>) entries;
         } else {
@@ -517,8 +510,6 @@ public static <K, V> LinkedHashMap<K, V> ofEntries(Iterable<? extends Tuple2<? e
 
     @Override
     public <K2, V2> LinkedHashMap<K2, V2> bimap(Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         final Iterator<Tuple2<K2, V2>> entries = iterator().map(entry -> Tuple.of(keyMapper.apply(entry._1), valueMapper.apply(entry._2)));
         return LinkedHashMap.ofEntries(entries);
     }
@@ -615,7 +606,6 @@ public LinkedHashMap<K, V> filterNotValues(Predicate<? super V> predicate) {
 
     @Override
     public <K2, V2> LinkedHashMap<K2, V2> flatMap(BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2, V2>>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(LinkedHashMap.<K2, V2> empty(), (acc, entry) -> {
             for (Tuple2<? extends K2, ? extends V2> mappedEntry : mapper.apply(entry._1, entry._2)) {
                 acc = acc.put(mappedEntry);
@@ -711,13 +701,11 @@ public Tuple2<K, V> last() {
 
     @Override
     public <K2, V2> LinkedHashMap<K2, V2> map(BiFunction<? super K, ? super V, Tuple2<K2, V2>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return foldLeft(LinkedHashMap.empty(), (acc, entry) -> acc.put(entry.map(mapper)));
     }
 
     @Override
     public <K2> LinkedHashMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return map((k, v) -> Tuple.of(keyMapper.apply(k), v));
     }
 
@@ -728,7 +716,6 @@ public <K2> LinkedHashMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMa
 
     @Override
     public <W> LinkedHashMap<K, W> mapValues(Function<? super V, ? extends W> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return map((k, v) -> Tuple.of(k, mapper.apply(v)));
     }
 
@@ -816,7 +803,6 @@ public LinkedHashMap<K, V> remove(K key) {
 
     @Override
     public LinkedHashMap<K, V> removeAll(Iterable<? extends K> keys) {
-        Objects.requireNonNull(keys, "keys is null");
         final HashSet<K> toRemove = HashSet.ofAll(keys);
         final Queue<Tuple2<K, V>> newList = list.filter(t -> !toRemove.contains(t._1));
         final HashMap<K, V> newMap = map.filter(t -> !toRemove.contains(t._1));
@@ -825,8 +811,6 @@ public LinkedHashMap<K, V> removeAll(Iterable<? extends K> keys) {
 
     @Override
     public LinkedHashMap<K, V> replace(Tuple2<K, V> currentElement, Tuple2<K, V> newElement) {
-        Objects.requireNonNull(currentElement, "currentElement is null");
-        Objects.requireNonNull(newElement, "newElement is null");
 
         // We replace the whole element, i.e. key and value have to be present.
         if (!Objects.equals(currentElement, newElement) && contains(currentElement)) {
@@ -878,7 +862,6 @@ public LinkedHashMap<K, V> replaceAll(BiFunction<? super K, ? super V, ? extends
 
     @Override
     public LinkedHashMap<K, V> retainAll(Iterable<? extends Tuple2<K, V>> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         LinkedHashMap<K, V> result = empty();
         for (Tuple2<K, V> entry : elements) {
             if (contains(entry)) {
diff --git a/src/main/java/io/vavr/collection/LinkedHashMultimap.java b/src/main/java/io/vavr/collection/LinkedHashMultimap.java
index 4dca8a267..8f4f50c98 100644
--- a/src/main/java/io/vavr/collection/LinkedHashMultimap.java
+++ b/src/main/java/io/vavr/collection/LinkedHashMultimap.java
@@ -96,7 +96,6 @@ public <K, V2 extends V> LinkedHashMultimap<K, V2> empty() {
          * @return A new LinkedHashMultimap containing the given entries.
          */
         public <K, V2 extends V> LinkedHashMultimap<K, V2> ofEntries(Iterable<? extends Tuple2<? extends K, ? extends V2>> entries) {
-            Objects.requireNonNull(entries, "entries is null");
             LinkedHashMultimap<K, V2> result = empty();
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -114,7 +113,6 @@ public <K, V2 extends V> LinkedHashMultimap<K, V2> ofEntries(Iterable<? extends
          */
         @SafeVarargs
         public final <K, V2 extends V> LinkedHashMultimap<K, V2> ofEntries(Tuple2<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(entries, "entries is null");
             LinkedHashMultimap<K, V2> result = empty();
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -132,7 +130,6 @@ public final <K, V2 extends V> LinkedHashMultimap<K, V2> ofEntries(Tuple2<? exte
          */
         @SafeVarargs
         public final <K, V2 extends V> LinkedHashMultimap<K, V2> ofEntries(java.util.Map.Entry<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(entries, "entries is null");
             LinkedHashMultimap<K, V2> result = empty();
             for (java.util.Map.Entry<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry.getKey(), entry.getValue());
@@ -197,7 +194,6 @@ public <T, K, V2 extends V> LinkedHashMultimap<K, V2> ofAll(java.util.stream.Str
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> LinkedHashMultimap<K, V2> tabulate(int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V2>> f) {
-            Objects.requireNonNull(f, "f is null");
             return ofEntries(Collections.tabulate(n, (Function<? super Integer, ? extends Tuple2<K, V2>>) f));
         }
 
@@ -213,7 +209,6 @@ public <K, V2 extends V> LinkedHashMultimap<K, V2> tabulate(int n, Function<? su
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> LinkedHashMultimap<K, V2> fill(int n, Supplier<? extends Tuple2<? extends K, ? extends V2>> s) {
-            Objects.requireNonNull(s, "s is null");
             return ofEntries(Collections.fill(n, (Supplier<? extends Tuple2<K, V2>>) s));
         }
 
diff --git a/src/main/java/io/vavr/collection/LinkedHashSet.java b/src/main/java/io/vavr/collection/LinkedHashSet.java
index 842778ece..e1018ac69 100644
--- a/src/main/java/io/vavr/collection/LinkedHashSet.java
+++ b/src/main/java/io/vavr/collection/LinkedHashSet.java
@@ -112,7 +112,6 @@ public static <T> LinkedHashSet<T> of(T element) {
      */
     @SafeVarargs
     public static <T> LinkedHashSet<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         LinkedHashMap<T, Object> map = LinkedHashMap.empty();
         for (T element : elements) {
             map = map.put(element, element);
@@ -131,7 +130,6 @@ public static <T> LinkedHashSet<T> of(T... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> LinkedHashSet<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return Collections.tabulate(n, f, LinkedHashSet.empty(), LinkedHashSet::of);
     }
 
@@ -145,7 +143,6 @@ public static <T> LinkedHashSet<T> tabulate(int n, Function<? super Integer, ? e
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> LinkedHashSet<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return Collections.fill(n, s, LinkedHashSet.empty(), LinkedHashSet::of);
     }
 
@@ -158,7 +155,6 @@ public static <T> LinkedHashSet<T> fill(int n, Supplier<? extends T> s) {
      */
     @SuppressWarnings("unchecked")
     public static <T> LinkedHashSet<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof LinkedHashSet) {
             return (LinkedHashSet<T>) elements;
         } else {
@@ -175,7 +171,6 @@ public static <T> LinkedHashSet<T> ofAll(Iterable<? extends T> elements) {
      * @return A LinkedHashSet containing the given elements in the same order.
      */
     public static <T> LinkedHashSet<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return ofAll(Iterator.ofAll(javaStream.iterator()));
     }
 
@@ -187,7 +182,6 @@ public static <T> LinkedHashSet<T> ofAll(java.util.stream.Stream<? extends T> ja
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -199,7 +193,6 @@ public static LinkedHashSet<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -211,7 +204,6 @@ public static LinkedHashSet<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -223,7 +215,6 @@ public static LinkedHashSet<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -235,7 +226,6 @@ public static LinkedHashSet<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -247,7 +237,6 @@ public static LinkedHashSet<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -259,7 +248,6 @@ public static LinkedHashSet<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -271,7 +259,6 @@ public static LinkedHashSet<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static LinkedHashSet<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return LinkedHashSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -506,7 +493,6 @@ public LinkedHashSet<T> add(T element) {
      */
     @Override
     public LinkedHashSet<T> addAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() && elements instanceof LinkedHashSet) {
             @SuppressWarnings("unchecked")
             final LinkedHashSet<T> set = (LinkedHashSet<T>) elements;
@@ -532,7 +518,6 @@ public boolean contains(T element) {
 
     @Override
     public LinkedHashSet<T> diff(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() || elements.isEmpty()) {
             return this;
         } else {
@@ -547,13 +532,11 @@ public LinkedHashSet<T> distinct() {
 
     @Override
     public LinkedHashSet<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return LinkedHashSet.ofAll(iterator().distinctBy(comparator));
     }
 
     @Override
     public <U> LinkedHashSet<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return LinkedHashSet.ofAll(iterator().distinctBy(keyExtractor));
     }
 
@@ -577,33 +560,28 @@ public LinkedHashSet<T> dropRight(int n) {
 
     @Override
     public LinkedHashSet<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public LinkedHashSet<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final LinkedHashSet<T> dropped = LinkedHashSet.ofAll(iterator().dropWhile(predicate));
         return dropped.length() == length() ? this : dropped;
     }
 
     @Override
     public LinkedHashSet<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final LinkedHashSet<T> filtered = LinkedHashSet.ofAll(iterator().filter(predicate));
         return filtered.length() == length() ? this : filtered;
     }
 
     @Override
     public LinkedHashSet<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
     @Override
     public <U> LinkedHashSet<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -615,7 +593,6 @@ public <U> LinkedHashSet<U> flatMap(Function<? super T, ? extends Iterable<? ext
 
     @Override
     public <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return iterator().foldRight(zero, f);
     }
 
@@ -663,7 +640,6 @@ public Option<LinkedHashSet<T>> initOption() {
 
     @Override
     public LinkedHashSet<T> intersect(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() || elements.isEmpty()) {
             return empty();
         } else {
@@ -723,7 +699,6 @@ public int length() {
 
     @Override
     public <U> LinkedHashSet<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -757,7 +732,6 @@ public Tuple2<LinkedHashSet<T>, LinkedHashSet<T>> partition(Predicate<? super T>
 
     @Override
     public LinkedHashSet<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(iterator().head());
         }
@@ -829,7 +803,6 @@ public Iterator<LinkedHashSet<T>> sliding(int size, int step) {
 
     @Override
     public Tuple2<LinkedHashSet<T>, LinkedHashSet<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Tuple2<Iterator<T>, Iterator<T>> t = iterator().span(predicate);
         return Tuple.of(LinkedHashSet.ofAll(t._1), LinkedHashSet.ofAll(t._2));
     }
@@ -865,13 +838,11 @@ public LinkedHashSet<T> takeRight(int n) {
 
     @Override
     public LinkedHashSet<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @Override
     public LinkedHashSet<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final LinkedHashSet<T> taken = LinkedHashSet.ofAll(iterator().takeWhile(predicate));
         return taken.length() == length() ? this : taken;
     }
@@ -885,7 +856,6 @@ public LinkedHashSet<T> takeWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super LinkedHashSet<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -907,7 +877,6 @@ public java.util.LinkedHashSet<T> toJavaSet() {
     @SuppressWarnings("unchecked")
     @Override
     public LinkedHashSet<T> union(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty()) {
             if (elements instanceof LinkedHashSet) {
                 return (LinkedHashSet<T>) elements;
@@ -933,14 +902,11 @@ public <U> LinkedHashSet<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> LinkedHashSet<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return LinkedHashSet.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> LinkedHashSet<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return LinkedHashSet.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -951,7 +917,6 @@ public LinkedHashSet<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> LinkedHashSet<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return LinkedHashSet.ofAll(iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/List.java b/src/main/java/io/vavr/collection/List.java
index a6e48ed74..cb0411936 100644
--- a/src/main/java/io/vavr/collection/List.java
+++ b/src/main/java/io/vavr/collection/List.java
@@ -220,7 +220,6 @@ public static <T> List<T> of(T element) {
      */
     @SafeVarargs
     public static <T> List<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         List<T> result = Nil.instance();
         for (int i = elements.length - 1; i >= 0; i--) {
             result = result.prepend(elements[i]);
@@ -241,7 +240,6 @@ public static <T> List<T> of(T... elements) {
      */
     @SuppressWarnings("unchecked")
     public static <T> List<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof List) {
             return (List<T>) elements;
         } else if (elements instanceof ListView
@@ -279,7 +277,6 @@ public static <T> List<T> ofAll(Iterable<? extends T> elements) {
      * @return A List containing the given elements in the same order.
      */
     public static <T> List<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         final java.util.Iterator<? extends T> iterator = javaStream.iterator();
         List<T> list = List.empty();
         while (iterator.hasNext()) {
@@ -296,7 +293,6 @@ public static <T> List<T> ofAll(java.util.stream.Stream<? extends T> javaStream)
      * @throws NullPointerException if elements is null
      */
     public static List<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -308,7 +304,6 @@ public static List<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -320,7 +315,6 @@ public static List<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -332,7 +326,6 @@ public static List<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -344,7 +337,6 @@ public static List<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -356,7 +348,6 @@ public static List<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -368,7 +359,6 @@ public static List<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -380,7 +370,6 @@ public static List<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static List<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(Iterator.ofAll(elements));
     }
 
@@ -395,7 +384,6 @@ public static List<Short> ofAll(short... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> List<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return Collections.tabulate(n, f, empty(), List::of);
     }
 
@@ -409,7 +397,6 @@ public static <T> List<T> tabulate(int n, Function<? super Integer, ? extends T>
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> List<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return Collections.fill(n, s, empty(), List::of);
     }
 
@@ -744,7 +731,6 @@ public final List<T> append(T element) {
 
     @Override
     public final List<T> appendAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return List.<T> ofAll(elements).prependAll(this);
     }
 
@@ -795,14 +781,12 @@ public final List<T> distinct() {
 
     @Override
     public final List<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final java.util.Set<T> seen = new java.util.TreeSet<>(comparator);
         return filter(seen::add);
     }
 
     @Override
     public final <U> List<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         final java.util.Set<U> seen = new java.util.HashSet<>();
         return filter(t -> seen.add(keyExtractor.apply(t)));
     }
@@ -824,13 +808,11 @@ public final List<T> drop(int n) {
 
     @Override
     public final List<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public final List<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         List<T> list = this;
         while (!list.isEmpty() && predicate.test(list.head())) {
             list = list.tail();
@@ -851,19 +833,16 @@ public final List<T> dropRight(int n) {
 
     @Override
     public final List<T> dropRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return reverse().dropUntil(predicate).reverse();
     }
 
     @Override
     public final List<T> dropRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
     @Override
     public final List<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -880,13 +859,11 @@ public final List<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public final List<T> filterNot(Predicate<? super T> predicate){
-        Objects.requireNonNull(predicate, "predicate is null");
         return Collections.filterNot(this, predicate);
     }
 
     @Override
     public final <U> List<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         List<U> list = empty();
         for (T t : this) {
             for (U u : mapper.apply(t)) {
@@ -981,7 +958,6 @@ public final List<T> insert(int index, T element) {
 
     @Override
     public final List<T> insertAll(int index, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (index < 0) {
             throw new IndexOutOfBoundsException("insertAll(" + index + ", elements)");
         }
@@ -1028,7 +1004,6 @@ public final int lastIndexOf(T element, int end) {
 
     @Override
     public final <U> List<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         List<U> list = empty();
         for (T t : this) {
             list = list.prepend(mapper.apply(t));
@@ -1078,7 +1053,6 @@ public final List<T> patch(int from, Iterable<? extends T> that, int replaced) {
 
     @Override
     public final Tuple2<List<T>, List<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         List<T> left = empty(), right = empty();
         for (T t : this) {
             if (predicate.test(t)) {
@@ -1124,7 +1098,6 @@ public final Option<T> peekOption() {
      */
     @Override
     public final List<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -1208,7 +1181,6 @@ public final List<T> prepend(T element) {
 
     @Override
     public final List<T> prependAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return isEmpty() ? ofAll(elements) : ofAll(elements).reverse().foldLeft(this, List::prepend);
     }
 
@@ -1236,7 +1208,6 @@ public final List<T> push(T element) {
     @Deprecated
     @SuppressWarnings("unchecked")
     public final List<T> push(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         List<T> result = this;
         for (T element : elements) {
             result = result.prepend(element);
@@ -1255,7 +1226,6 @@ public final List<T> push(T... elements) {
      */
     @Deprecated
     public final List<T> pushAll(Iterable<T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         List<T> result = this;
         for (T element : elements) {
             result = result.prepend(element);
@@ -1288,7 +1258,6 @@ public final List<T> remove(T element) {
 
     @Override
     public final List<T> removeFirst(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         List<T> init = empty();
         List<T> tail = this;
         while (!tail.isEmpty() && !predicate.test(tail.head())) {
@@ -1304,7 +1273,6 @@ public final List<T> removeFirst(Predicate<T> predicate) {
 
     @Override
     public final List<T> removeLast(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final List<T> removedAndReversed = reverse().removeFirst(predicate);
         return removedAndReversed.length() == length() ? this : removedAndReversed.reverse();
     }
@@ -1461,7 +1429,6 @@ public final List<T> sorted() {
 
     @Override
     public final List<T> sorted(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : toJavaStream().sorted(comparator).collect(collector());
     }
 
@@ -1477,7 +1444,6 @@ public final <U> List<T> sortBy(Comparator<? super U> comparator, Function<? sup
 
     @Override
     public final Tuple2<List<T>, List<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Tuple2<Iterator<T>, Iterator<T>> itt = iterator().span(predicate);
         return Tuple.of(ofAll(itt._1), ofAll(itt._2));
     }
@@ -1585,13 +1551,11 @@ public final List<T> take(int n) {
 
     @Override
     public final List<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @Override
     public final List<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         List<T> result = Nil.instance();
         for (List<T> list = this; !list.isEmpty() && predicate.test(list.head()); list = list.tail()) {
             result = result.prepend(list.head());
@@ -1612,13 +1576,11 @@ public final List<T> takeRight(int n) {
 
     @Override
     public final List<T> takeRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightWhile(predicate.negate());
     }
 
     @Override
     public final List<T> takeRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return reverse().takeWhile(predicate).reverse();
     }
 
@@ -1631,7 +1593,6 @@ public final List<T> takeRightWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super List<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1664,7 +1625,6 @@ public final List<T> update(int index, T element) {
 
     @Override
     public final List<T> update(int index, Function<? super T, ? extends T> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         return update(index, updater.apply(get(index)));
     }
 
@@ -1675,14 +1635,11 @@ public final <U> List<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public final <U, R> List<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public final <U> List<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -1693,7 +1650,6 @@ public final List<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public final <U> List<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWithIndex(mapper));
     }
 
@@ -1953,7 +1909,6 @@ static <T> List<List<T>> apply(List<T> elements, int k) {
     private interface SplitAt {
 
         static <T> Tuple2<List<T>, List<T>> splitByPredicateReversed(List<T> source, Predicate<? super T> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             List<T> init = Nil.instance();
             List<T> tail = source;
             while (!tail.isEmpty() && !predicate.test(tail.head())) {
diff --git a/src/main/java/io/vavr/collection/Map.java b/src/main/java/io/vavr/collection/Map.java
index fbf4a3105..d42b1d36b 100644
--- a/src/main/java/io/vavr/collection/Map.java
+++ b/src/main/java/io/vavr/collection/Map.java
@@ -315,14 +315,12 @@ default boolean containsValue(V value) {
     @SuppressWarnings("unchecked")
     @Override
     default <U> Seq<U> flatMap(Function<? super Tuple2<K, V>, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         // don't remove cast, doesn't compile in Eclipse without it
         return (Seq<U>) iterator().flatMap(mapper).toStream();
     }
 
     @Override
     default <U> U foldRight(U zero, BiFunction<? super Tuple2<K, V>, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return iterator().foldRight(zero, f);
     }
 
@@ -333,7 +331,6 @@ default <U> U foldRight(U zero, BiFunction<? super Tuple2<K, V>, ? super U, ? ex
      * @throws NullPointerException if {@code action} is null
      */
     default void forEach(BiConsumer<K, V> action) {
-        Objects.requireNonNull(action, "action is null");
         for (Tuple2<K, V> t : this) {
             action.accept(t._1, t._2);
         }
@@ -380,7 +377,6 @@ default boolean isTraversableAgain() {
      * @return An iterator through the mapped elements.
      */
     default <U> Iterator<U> iterator(BiFunction<K, V, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return iterator().map(t -> mapper.apply(t._1, t._2));
     }
 
@@ -426,7 +422,6 @@ default Function1<K, Option<V>> lift() {
     @SuppressWarnings("unchecked")
     @Override
     default <U> Seq<U> map(Function<? super Tuple2<K, V>, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         // don't remove cast, doesn't compile in Eclipse without it
         return (Seq<U>) iterator().map(mapper).toStream();
     }
@@ -597,7 +592,6 @@ default <U> Seq<U> scanRight(U zero, BiFunction<? super Tuple2<K, V>, ? super U,
      * @throws NullPointerException if {@code f} is null
      */
     default <U> U transform(Function<? super Map<K, V>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -638,14 +632,11 @@ default <U> Seq<Tuple2<Tuple2<K, V>, U>> zip(Iterable<? extends U> that) {
 
     @Override
     default <U, R> Seq<R> zipWith(Iterable<? extends U> that, BiFunction<? super Tuple2<K, V>, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     default <U> Seq<Tuple2<Tuple2<K, V>, U>> zipAll(Iterable<? extends U> that, Tuple2<K, V> thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return Stream.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -656,7 +647,6 @@ default Seq<Tuple2<Tuple2<K, V>, Integer>> zipWithIndex() {
 
     @Override
     default <U> Seq<U> zipWithIndex(BiFunction<? super Tuple2<K, V>, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/Maps.java b/src/main/java/io/vavr/collection/Maps.java
index 90fbf4486..ad4553417 100644
--- a/src/main/java/io/vavr/collection/Maps.java
+++ b/src/main/java/io/vavr/collection/Maps.java
@@ -46,7 +46,6 @@ private Maps() {
 
     @SuppressWarnings("unchecked")
     static <K, V, M extends Map<K, V>> Tuple2<V, M> computeIfAbsent(M map, K key, Function<? super K, ? extends V> mappingFunction) {
-        Objects.requireNonNull(mappingFunction, "mappingFunction is null");
         final Option<V> value = map.get(key);
         if (value.isDefined()) {
             return Tuple.of(value.get(), map);
@@ -75,13 +74,11 @@ static <K, V, M extends Map<K, V>> M distinct(M map) {
 
     static <K, V, M extends Map<K, V>> M distinctBy(M map, OfEntries<K, V, M> ofEntries,
             Comparator<? super Tuple2<K, V>> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return ofEntries.apply(map.iterator().distinctBy(comparator));
     }
 
     static <K, V, U, M extends Map<K, V>> M distinctBy(
             M map, OfEntries<K, V, M> ofEntries, Function<? super Tuple2<K, V>, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return ofEntries.apply(map.iterator().distinctBy(keyExtractor));
     }
 
@@ -108,37 +105,31 @@ static <K, V, M extends Map<K, V>> M dropRight(M map, OfEntries<K, V, M> ofEntri
 
     static <K, V, M extends Map<K, V>> M dropUntil(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(map, ofEntries, predicate.negate());
     }
 
     static <K, V, M extends Map<K, V>> M dropWhile(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return ofEntries.apply(map.iterator().dropWhile(predicate));
     }
 
     static <K, V, M extends Map<K, V>> M filter(M map, OfEntries<K, V, M> ofEntries,
             BiPredicate<? super K, ? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(map, ofEntries, t -> predicate.test(t._1, t._2));
     }
 
     static <K, V, M extends Map<K, V>> M filter(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return ofEntries.apply(map.iterator().filter(predicate));
     }
 
     static <K, V, M extends Map<K, V>> M filterKeys(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super K> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(map, ofEntries, t -> predicate.test(t._1));
     }
 
     static <K, V, M extends Map<K, V>> M filterValues(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(map, ofEntries, t -> predicate.test(t._2));
     }
 
@@ -158,7 +149,6 @@ static <K, V, M extends Map<K, V>> Option<M> initOption(M map) {
 
     static <K, V, M extends Map<K, V>> M merge(M map, OfEntries<K, V, M> ofEntries,
             Map<? extends K, ? extends V> that) {
-        Objects.requireNonNull(that, "that is null");
         if (map.isEmpty()) {
             return ofEntries.apply(Map.narrow(that));
         } else if (that.isEmpty()) {
@@ -172,8 +162,6 @@ static <K, V, M extends Map<K, V>> M merge(M map, OfEntries<K, V, M> ofEntries,
     static <K, V, U extends V, M extends Map<K, V>> M merge(
             M map, OfEntries<K, V, M> ofEntries,
             Map<? extends K, U> that, BiFunction<? super V, ? super U, ? extends V> collisionResolution) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(collisionResolution, "collisionResolution is null");
         if (map.isEmpty()) {
             return ofEntries.apply(Map.narrow(that));
         } else if (that.isEmpty()) {
@@ -192,23 +180,17 @@ static <K, V, U extends V, M extends Map<K, V>> M merge(
     static <T, K, V, M extends Map<K, V>> M ofStream(M map, java.util.stream.Stream<? extends T> stream,
             Function<? super T, ? extends K> keyMapper,
             Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(stream, "stream is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return Stream.ofAll(stream).foldLeft(map, (m, el) -> (M) m.put(keyMapper.apply(el), valueMapper.apply(el)));
     }
 
     @SuppressWarnings("unchecked")
     static <T, K, V, M extends Map<K, V>> M ofStream(M map, java.util.stream.Stream<? extends T> stream,
             Function<? super T, Tuple2<? extends K, ? extends V>> entryMapper) {
-        Objects.requireNonNull(stream, "stream is null");
-        Objects.requireNonNull(entryMapper, "entryMapper is null");
         return Stream.ofAll(stream).foldLeft(map, (m, el) -> (M) m.put(entryMapper.apply(el)));
     }
 
     static <K, V, M extends Map<K, V>> Tuple2<M, M> partition(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final java.util.List<Tuple2<K, V>> left = new java.util.ArrayList<>();
         final java.util.List<Tuple2<K, V>> right = new java.util.ArrayList<>();
         for (Tuple2<K, V> entry : map) {
@@ -218,7 +200,6 @@ static <K, V, M extends Map<K, V>> Tuple2<M, M> partition(M map, OfEntries<K, V,
     }
 
     static <K, V, M extends Map<K, V>> M peek(M map, Consumer<? super Tuple2<K, V>> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!map.isEmpty()) {
             action.accept(map.head());
         }
@@ -228,7 +209,6 @@ static <K, V, M extends Map<K, V>> M peek(M map, Consumer<? super Tuple2<K, V>>
     @SuppressWarnings("unchecked")
     static <K, V, U extends V, M extends Map<K, V>> M put(M map, K key, U value,
             BiFunction<? super V, ? super U, ? extends V> merge) {
-        Objects.requireNonNull(merge, "the merge function is null");
         final Option<V> currentValue = map.get(key);
         if (currentValue.isEmpty()) {
             return (M) map.put(key, value);
@@ -239,13 +219,11 @@ static <K, V, U extends V, M extends Map<K, V>> M put(M map, K key, U value,
 
     @SuppressWarnings("unchecked")
     static <K, V, M extends Map<K, V>> M put(M map, Tuple2<? extends K, ? extends V> entry) {
-        Objects.requireNonNull(entry, "entry is null");
         return (M) map.put(entry._1, entry._2);
     }
 
     static <K, V, U extends V, M extends Map<K, V>> M put(M map, Tuple2<? extends K, U> entry,
             BiFunction<? super V, ? super U, ? extends V> merge) {
-        Objects.requireNonNull(merge, "the merge function is null");
         final Option<V> currentValue = map.get(entry._1);
         if (currentValue.isEmpty()) {
             return put(map, entry);
@@ -256,25 +234,21 @@ static <K, V, U extends V, M extends Map<K, V>> M put(M map, Tuple2<? extends K,
 
     static <K, V, M extends Map<K, V>> M filterNot(M map, OfEntries<K, V, M> ofEntries,
                                                 Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(map, ofEntries, predicate.negate());
     }
 
     static <K, V, M extends Map<K, V>> M filterNot(M map, OfEntries<K, V, M> ofEntries,
                                                 BiPredicate<? super K, ? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(map, ofEntries, predicate.negate());
     }
 
     static <K, V, M extends Map<K, V>> M filterNotKeys(M map, OfEntries<K, V, M> ofEntries,
                                                     Predicate<? super K> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterKeys(map, ofEntries, predicate.negate());
     }
 
     static <K, V, M extends Map<K, V>> M filterNotValues(M map, OfEntries<K, V, M> ofEntries,
                                                       Predicate<? super V> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterValues(map, ofEntries, predicate.negate());
     }
 
@@ -285,8 +259,6 @@ static <K, V, M extends Map<K, V>> M replace(M map, K key, V oldValue, V newValu
 
     @SuppressWarnings("unchecked")
     static <K, V, M extends Map<K, V>> M replace(M map, Tuple2<K, V> currentElement, Tuple2<K, V> newElement) {
-        Objects.requireNonNull(currentElement, "currentElement is null");
-        Objects.requireNonNull(newElement, "newElement is null");
         return (M) (map.containsKey(currentElement._1) ? map.remove(currentElement._1).put(newElement) : map);
     }
 
@@ -326,7 +298,6 @@ static <K, V, M extends Map<K, V>> Iterator<M> sliding(M map, OfEntries<K, V, M>
 
     static <K, V, M extends Map<K, V>> Tuple2<M, M> span(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Tuple2<Iterator<Tuple2<K, V>>, Iterator<Tuple2<K, V>>> t = map.iterator().span(predicate);
         return Tuple.of(ofEntries.apply(t._1), ofEntries.apply(t._2));
     }
@@ -354,13 +325,11 @@ static <K, V, M extends Map<K, V>> M takeRight(M map, OfEntries<K, V, M> ofEntri
 
     static <K, V, M extends Map<K, V>> M takeUntil(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(map, ofEntries, predicate.negate());
     }
 
     static <K, V, M extends Map<K, V>> M takeWhile(M map, OfEntries<K, V, M> ofEntries,
             Predicate<? super Tuple2<K, V>> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final M taken = ofEntries.apply(map.iterator().takeWhile(predicate));
         return taken.size() == map.size() ? map : taken;
     }
diff --git a/src/main/java/io/vavr/collection/Multimap.java b/src/main/java/io/vavr/collection/Multimap.java
index d566ea543..f5e370edb 100644
--- a/src/main/java/io/vavr/collection/Multimap.java
+++ b/src/main/java/io/vavr/collection/Multimap.java
@@ -311,7 +311,6 @@ default boolean containsValue(V value) {
      * @throws NullPointerException if {@code action} is null
      */
     default void forEach(BiConsumer<K, V> action) {
-        Objects.requireNonNull(action, "action is null");
         for (Tuple2<K, V> t : this) {
             action.accept(t._1, t._2);
         }
@@ -376,7 +375,6 @@ default boolean isTraversableAgain() {
      * @return An iterator through the mapped elements.
      */
     default <U> Iterator<U> iterator(BiFunction<K, V, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return iterator().map(t -> mapper.apply(t._1, t._2));
     }
 
@@ -415,7 +413,6 @@ default int length() {
     @SuppressWarnings("unchecked")
     @Override
     default <U> Seq<U> map(Function<? super Tuple2<K, V>, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         // don't remove cast, doesn't compile in Eclipse without it
         return (Seq<U>) iterator().map(mapper).toStream();
     }
@@ -534,7 +531,6 @@ default <U> Seq<U> scanRight(U zero, BiFunction<? super Tuple2<K, V>, ? super U,
      * @throws NullPointerException if {@code f} is null
      */
     default <U> U transform(Function<? super Multimap<K, V>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -547,14 +543,11 @@ default <U> Seq<Tuple2<Tuple2<K, V>, U>> zip(Iterable<? extends U> that) {
 
     @Override
     default <U> Seq<Tuple2<Tuple2<K, V>, U>> zipAll(Iterable<? extends U> that, Tuple2<K, V> thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return Stream.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
     @Override
     default <U, R> Seq<R> zipWith(Iterable<? extends U> that, BiFunction<? super Tuple2<K, V>, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWith(that, mapper));
     }
 
@@ -565,7 +558,6 @@ default Seq<Tuple2<Tuple2<K, V>, Integer>> zipWithIndex() {
 
     @Override
     default <U> Seq<U> zipWithIndex(BiFunction<? super Tuple2<K, V>, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWithIndex(mapper));
     }
 
@@ -610,14 +602,12 @@ default <U> Seq<U> zipWithIndex(BiFunction<? super Tuple2<K, V>, ? super Integer
     @SuppressWarnings("unchecked")
     @Override
     default <U> Seq<U> flatMap(Function<? super Tuple2<K, V>, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         // don't remove cast, doesn't compile in Eclipse without it
         return (Seq<U>) iterator().flatMap(mapper).toStream();
     }
 
     @Override
     default <U> U foldRight(U zero, BiFunction<? super Tuple2<K, V>, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return iterator().foldRight(zero, f);
     }
 
diff --git a/src/main/java/io/vavr/collection/Multimaps.java b/src/main/java/io/vavr/collection/Multimaps.java
index 3be274924..4a930d4eb 100644
--- a/src/main/java/io/vavr/collection/Multimaps.java
+++ b/src/main/java/io/vavr/collection/Multimaps.java
@@ -38,7 +38,6 @@ class Multimaps {
 
     @SuppressWarnings("unchecked")
     static <K, V, M extends Multimap<K, V>> M ofJavaMap(M source, java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         return Stream.ofAll(map.entrySet()).foldLeft(source, (m, el) -> (M) m.put(el.getKey(), el.getValue()));
     }
 
@@ -46,17 +45,12 @@ static <K, V, M extends Multimap<K, V>> M ofJavaMap(M source, java.util.Map<? ex
     static <T, K, V, M extends Multimap<K, V>> M ofStream(M source, java.util.stream.Stream<? extends T> stream,
                                                      Function<? super T, ? extends K> keyMapper,
                                                      Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(stream, "stream is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return Stream.ofAll(stream).foldLeft(source, (m, el) -> (M) m.put(keyMapper.apply(el), valueMapper.apply(el)));
     }
 
     @SuppressWarnings("unchecked")
     static <T, K, V, M extends Multimap<K, V>> M ofStream(M source, java.util.stream.Stream<? extends T> stream,
                                                      Function<? super T, Tuple2<? extends K, ? extends V>> entryMapper) {
-        Objects.requireNonNull(stream, "stream is null");
-        Objects.requireNonNull(entryMapper, "entryMapper is null");
         return Stream.ofAll(stream).foldLeft(source, (m, el) -> (M) m.put(entryMapper.apply(el)));
     }
 }
diff --git a/src/main/java/io/vavr/collection/PriorityQueue.java b/src/main/java/io/vavr/collection/PriorityQueue.java
index 6baa1a133..4cb13fe5a 100644
--- a/src/main/java/io/vavr/collection/PriorityQueue.java
+++ b/src/main/java/io/vavr/collection/PriorityQueue.java
@@ -233,7 +233,6 @@ public static <T extends Comparable<? super T>> PriorityQueue<T> ofAll(Iterable<
 
     @SuppressWarnings("unchecked")
     public static <T> PriorityQueue<T> ofAll(Comparator<? super T> comparator, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof PriorityQueue && ((PriorityQueue) elements).comparator == comparator) {
             return (PriorityQueue<T>) elements;
         } else {
@@ -266,7 +265,6 @@ public static <T> PriorityQueue<T> ofAll(Comparator<? super T> comparator, java.
      * @throws NullPointerException if {@code function} is null
      */
     public static <T> PriorityQueue<T> tabulate(int size, Function<? super Integer, ? extends T> function) {
-        Objects.requireNonNull(function, "function is null");
         final Comparator<? super T> comparator = Comparators.naturalComparator();
         return io.vavr.collection.Collections.tabulate(size, function, empty(comparator), values -> ofAll(comparator, io.vavr.collection.List.of(values)));
     }
@@ -282,7 +280,6 @@ public static <T> PriorityQueue<T> tabulate(int size, Function<? super Integer,
      */
     @SuppressWarnings("unchecked")
     public static <T> PriorityQueue<T> fill(int size, Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         final Comparator<? super T> comparator = Comparators.naturalComparator();
         return io.vavr.collection.Collections.fill(size, supplier, empty(comparator), values -> ofAll(comparator, io.vavr.collection.List.of(values)));
     }
@@ -321,7 +318,6 @@ public io.vavr.collection.List<T> toList() {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super PriorityQueue<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -332,13 +328,11 @@ public PriorityQueue<T> distinct() {
 
     @Override
     public PriorityQueue<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : ofAll(comparator, iterator().distinctBy(comparator));
     }
 
     @Override
     public <U> PriorityQueue<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return isEmpty() ? this : ofAll(comparator, iterator().distinctBy(keyExtractor));
     }
 
@@ -366,7 +360,6 @@ public PriorityQueue<T> dropRight(int n) {
 
     @Override
     public PriorityQueue<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         PriorityQueue<T> result = this;
         while (!result.isEmpty() && predicate.test(result.head())) {
             result = result.tail();
@@ -376,7 +369,6 @@ public PriorityQueue<T> dropWhile(Predicate<? super T> predicate) {
 
     @Override
     public PriorityQueue<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -390,8 +382,6 @@ public <U> PriorityQueue<U> flatMap(Function<? super T, ? extends Iterable<? ext
     }
 
     public <U> PriorityQueue<U> flatMap(Comparator<U> comparator, Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(comparator, iterator().flatMap(mapper));
     }
 
@@ -408,8 +398,6 @@ public <U> PriorityQueue<U> flatMap(Comparator<U> comparator, Function<? super T
      */
     @Override
     public <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> accumulator) {
-        Objects.requireNonNull(zero, "zero is null");
-        Objects.requireNonNull(accumulator, "accumulator is null");
         return toList().foldRight(zero, accumulator);
     }
 
@@ -477,13 +465,10 @@ public int length() {
 
     @Override
     public <U> PriorityQueue<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return map(Comparators.naturalComparator(), mapper);
     }
 
     public <U> PriorityQueue<U> map(Comparator<U> comparator, Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(comparator, iterator().map(mapper));
     }
 
@@ -515,7 +500,6 @@ public PriorityQueue<T> orElse(Supplier<? extends Iterable<? extends T>> supplie
 
     @Override
     public Tuple2<? extends PriorityQueue<T>, ? extends PriorityQueue<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         PriorityQueue<T> left = empty(comparator), right = left;
         for (T t : this) {
             if (predicate.test(t)) {
@@ -530,15 +514,11 @@ public PriorityQueue<T> orElse(Supplier<? extends Iterable<? extends T>> supplie
 
     @Override
     public PriorityQueue<T> replace(T currentElement, T newElement) {
-        Objects.requireNonNull(currentElement, "currentElement is null");
-        Objects.requireNonNull(newElement, "newElement is null");
         return ofAll(comparator, iterator().replace(currentElement, newElement));
     }
 
     @Override
     public PriorityQueue<T> replaceAll(T currentElement, T newElement) {
-        Objects.requireNonNull(currentElement, "currentElement is null");
-        Objects.requireNonNull(newElement, "newElement is null");
         return ofAll(comparator, iterator().replaceAll(currentElement, newElement));
     }
 
@@ -574,7 +554,6 @@ public io.vavr.collection.Iterator<? extends PriorityQueue<T>> sliding(int size,
 
     @Override
     public Tuple2<? extends PriorityQueue<T>, ? extends PriorityQueue<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Tuple.of(takeWhile(predicate), dropWhile(predicate));
     }
 
@@ -602,26 +581,21 @@ public PriorityQueue<T> takeRight(int n) {
 
     @Override
     public PriorityQueue<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return isEmpty() ? this : ofAll(comparator, iterator().takeUntil(predicate));
     }
 
     @Override
     public <U> PriorityQueue<Tuple2<T, U>> zip(Iterable<? extends U> that) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(Tuple2.comparator(comparator(), Comparators.naturalComparator()), iterator().zipWith(that, Tuple::of));
     }
 
     @Override
     public <U, R> PriorityQueue<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(Comparators.naturalComparator(), iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> PriorityQueue<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(Tuple2.comparator(comparator(), Comparators.naturalComparator()), iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -632,7 +606,6 @@ public PriorityQueue<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> PriorityQueue<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(Comparators.naturalComparator(), iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/Queue.java b/src/main/java/io/vavr/collection/Queue.java
index 9a8237158..fd948c5e5 100644
--- a/src/main/java/io/vavr/collection/Queue.java
+++ b/src/main/java/io/vavr/collection/Queue.java
@@ -146,7 +146,6 @@ public static <T> Queue<T> of(T element) {
     @SuppressWarnings("varargs")
     @SafeVarargs
     public static <T> Queue<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.of(elements));
     }
 
@@ -160,7 +159,6 @@ public static <T> Queue<T> of(T... elements) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Queue<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof Queue) {
             return (Queue<T>) elements;
         } else if (elements instanceof ListView
@@ -183,7 +181,6 @@ public static <T> Queue<T> ofAll(Iterable<? extends T> elements) {
      * @return A Queue containing the given elements in the same order.
      */
     public static <T> Queue<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return new Queue<>(io.vavr.collection.List.ofAll(javaStream), io.vavr.collection.List.empty());
     }
 
@@ -195,7 +192,6 @@ public static <T> Queue<T> ofAll(java.util.stream.Stream<? extends T> javaStream
      * @throws NullPointerException if elements is null
      */
     public static Queue<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -207,7 +203,6 @@ public static Queue<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -219,7 +214,6 @@ public static Queue<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -231,7 +225,6 @@ public static Queue<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -243,7 +236,6 @@ public static Queue<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -255,7 +247,6 @@ public static Queue<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -267,7 +258,6 @@ public static Queue<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -279,7 +269,6 @@ public static Queue<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Queue<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(io.vavr.collection.List.ofAll(elements));
     }
 
@@ -294,7 +283,6 @@ public static Queue<Short> ofAll(short... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> Queue<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return io.vavr.collection.Collections.tabulate(n, f, empty(), Queue::of);
     }
 
@@ -308,7 +296,6 @@ public static <T> Queue<T> tabulate(int n, Function<? super Integer, ? extends T
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> Queue<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return io.vavr.collection.Collections.fill(n, s, empty(), Queue::of);
     }
 
@@ -656,7 +643,6 @@ public Queue<T> enqueue(T element) {
      */
     @SuppressWarnings("unchecked")
     public Queue<T> enqueueAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() && elements instanceof Queue) {
             return (Queue<T>) elements;
         } else {
@@ -723,13 +709,11 @@ public Queue<T> distinct() {
 
     @Override
     public Queue<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return ofAll(toList().distinctBy(comparator));
     }
 
     @Override
     public <U> Queue<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return ofAll(toList().distinctBy(keyExtractor));
     }
 
@@ -746,7 +730,6 @@ public Queue<T> drop(int n) {
 
     @Override
     public Queue<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final List<T> dropped = toList().dropWhile(predicate);
         return ofAll(dropped.length() == length() ? this : dropped);
     }
@@ -764,19 +747,16 @@ public Queue<T> dropRight(int n) {
 
     @Override
     public Queue<T> dropRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return reverse().dropUntil(predicate).reverse();
     }
 
     @Override
     public Queue<T> dropRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
     @Override
     public Queue<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final io.vavr.collection.List<T> filtered = toList().filter(predicate);
 
         if (filtered.isEmpty()) {
@@ -790,7 +770,6 @@ public Queue<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public <U> Queue<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return empty();
         } else {
@@ -890,7 +869,6 @@ public Queue<T> insert(int index, T element) {
     @SuppressWarnings("unchecked")
     @Override
     public Queue<T> insertAll(int index, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (index < 0) {
             throw new IndexOutOfBoundsException("insertAll(" + index + ", elements)");
         }
@@ -979,7 +957,6 @@ public boolean isDefinedAt(Integer index) {
 
     @Override
     public <U> Queue<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return new Queue<>(front.map(mapper), rear.map(mapper));
     }
 
@@ -1025,7 +1002,6 @@ public Queue<T> patch(int from, Iterable<? extends T> that, int replaced) {
 
     @Override
     public Tuple2<Queue<T>, Queue<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return toList().partition(predicate).map(io.vavr.collection.List::toQueue, io.vavr.collection.List::toQueue);
     }
 
@@ -1042,7 +1018,6 @@ public Queue<T> prepend(T element) {
     @SuppressWarnings("unchecked")
     @Override
     public Queue<T> prependAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty() && elements instanceof Queue) {
             return (Queue<T>) elements;
         } else {
@@ -1164,7 +1139,6 @@ public Queue<T> sorted() {
 
     @Override
     public Queue<T> sorted(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return ofAll(toList().sorted(comparator));
     }
 
@@ -1180,7 +1154,6 @@ public <U> Queue<T> sortBy(Comparator<? super U> comparator, Function<? super T,
 
     @Override
     public Tuple2<Queue<T>, Queue<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return toList().span(predicate).map(io.vavr.collection.List::toQueue, io.vavr.collection.List::toQueue);
     }
 
@@ -1254,7 +1227,6 @@ public Queue<T> take(int n) {
 
     @Override
     public Queue<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final io.vavr.collection.List<T> taken = toList().takeUntil(predicate);
         return taken.length() == length() ? this : ofAll(taken);
     }
@@ -1279,14 +1251,12 @@ public Queue<T> takeRight(int n) {
 
     @Override
     public Queue<T> takeRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final io.vavr.collection.List<T> taken = toList().takeRightUntil(predicate);
         return taken.length() == length() ? this : ofAll(taken);
     }
 
     @Override
     public Queue<T> takeRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightUntil(predicate.negate());
     }
 
@@ -1299,7 +1269,6 @@ public Queue<T> takeRightWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super Queue<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1310,7 +1279,6 @@ public Queue<T> update(int index, T element) {
 
     @Override
     public Queue<T> update(int index, Function<? super T, ? extends T> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         return update(index, updater.apply(get(index)));
     }
 
@@ -1322,14 +1290,11 @@ public <U> Queue<Tuple2<T, U>> zip(Iterable<? extends U> that) {
     @SuppressWarnings("unchecked")
     @Override
     public <U, R> Queue<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(toList().zipWith(that, mapper));
     }
 
     @Override
     public <U> Queue<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(toList().zipAll(that, thisElem, thatElem));
     }
 
@@ -1340,7 +1305,6 @@ public Queue<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> Queue<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(toList().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/collection/RedBlackTree.java b/src/main/java/io/vavr/collection/RedBlackTree.java
index 4ea3d9df8..13d6678da 100644
--- a/src/main/java/io/vavr/collection/RedBlackTree.java
+++ b/src/main/java/io/vavr/collection/RedBlackTree.java
@@ -53,20 +53,16 @@
 interface RedBlackTree<T> extends Iterable<T> {
 
     static <T> RedBlackTree<T> empty(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return new Empty<>(comparator);
     }
 
     static <T> RedBlackTree<T> of(Comparator<? super T> comparator, T value) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final Empty<T> empty = new Empty<>(comparator);
         return new Node<>(BLACK, 1, empty, value, empty, empty);
     }
 
     @SafeVarargs
     static <T> RedBlackTree<T> of(Comparator<? super T> comparator, T... values) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(values, "values is null");
         RedBlackTree<T> tree = empty(comparator);
         for (T value : values) {
             tree = tree.insert(value);
@@ -76,8 +72,6 @@ static <T> RedBlackTree<T> of(Comparator<? super T> comparator, T... values) {
 
     @SuppressWarnings("unchecked")
     static <T> RedBlackTree<T> ofAll(Comparator<? super T> comparator, Iterable<? extends T> values) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(values, "values is null");
         // function equality is not computable => same object check
         if (values instanceof RedBlackTree && ((RedBlackTree<T>) values).comparator() == comparator) {
             return (RedBlackTree<T>) values;
@@ -136,7 +130,6 @@ default RedBlackTree<T> delete(T value) {
     }
 
     default RedBlackTree<T> difference(RedBlackTree<T> tree) {
-        Objects.requireNonNull(tree, "tree is null");
         if (isEmpty() || tree.isEmpty()) {
             return this;
         } else {
@@ -166,7 +159,6 @@ default RedBlackTree<T> difference(RedBlackTree<T> tree) {
     Option<T> find(T value);
 
     default RedBlackTree<T> intersection(RedBlackTree<T> tree) {
-        Objects.requireNonNull(tree, "tree is null");
         if (isEmpty()) {
             return this;
         } else if (tree.isEmpty()) {
@@ -237,7 +229,6 @@ default Option<T> min() {
      * @return A new RedBlackTree that contains all distinct elements of this and the given {@code tree}.
      */
     default RedBlackTree<T> union(RedBlackTree<T> tree) {
-        Objects.requireNonNull(tree, "tree is null");
         if (tree.isEmpty()) {
             return this;
         } else {
diff --git a/src/main/java/io/vavr/collection/Seq.java b/src/main/java/io/vavr/collection/Seq.java
index 79bbcfbe3..21e12fe7e 100644
--- a/src/main/java/io/vavr/collection/Seq.java
+++ b/src/main/java/io/vavr/collection/Seq.java
@@ -265,7 +265,6 @@ static <T> Seq<T> narrow(Seq<? extends T> seq) {
      * @throws NullPointerException if {@code that} is null.
      */
     default boolean containsSlice(Iterable<? extends T> that) {
-        Objects.requireNonNull(that, "that is null");
         return indexOfSlice(that) >= 0;
     }
 
@@ -329,7 +328,6 @@ default Iterator<Tuple2<T, T>> crossProduct() {
      * @throws NullPointerException if that is null
      */
     default <U> Iterator<Tuple2<T, U>> crossProduct(Iterable<? extends U> that) {
-        Objects.requireNonNull(that, "that is null");
         final Stream<U> other = Stream.ofAll(that);
         return Iterator.ofAll(this).flatMap(a -> other.map(b -> Tuple.of(a, b)));
     }
@@ -343,7 +341,6 @@ default <U> Iterator<Tuple2<T, U>> crossProduct(Iterable<? extends U> that) {
      * @return true if this sequence has that as a suffix, false otherwise.
      */
     default boolean endsWith(Seq<? extends T> that) {
-        Objects.requireNonNull(that, "that is null");
         final Iterator<T> i = this.iterator().drop(length() - that.length());
         final Iterator<? extends T> j = that.iterator();
         while (i.hasNext() && j.hasNext()) {
@@ -1026,7 +1023,6 @@ default boolean startsWith(Iterable<? extends T> that) {
      * @return true if that is empty or that is prefix of this collection starting from the given offset, false otherwise.
      */
     default boolean startsWith(Iterable<? extends T> that, int offset) {
-        Objects.requireNonNull(that, "that is null");
         if (offset < 0) { return false; }
         final Iterator<T> i = this.iterator().drop(offset);
         final java.util.Iterator<? extends T> j = that.iterator();
@@ -1200,7 +1196,6 @@ default boolean startsWith(Iterable<? extends T> that, int offset) {
 
     @Override
     default <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return reverse().foldLeft(zero, (xs, x) -> f.apply(x, xs));
     }
 
diff --git a/src/main/java/io/vavr/collection/Stream.java b/src/main/java/io/vavr/collection/Stream.java
index 1cec7fd94..01e40117d 100644
--- a/src/main/java/io/vavr/collection/Stream.java
+++ b/src/main/java/io/vavr/collection/Stream.java
@@ -218,7 +218,6 @@ public static Stream<Long> from(long value, long step) {
      * @return A new Stream
      */
     public static <T> Stream<T> continually(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return Stream.ofAll(Iterator.continually(supplier));
     }
 
@@ -232,7 +231,6 @@ public static <T> Stream<T> continually(Supplier<? extends T> supplier) {
      * @return A new Stream
      */
     public static <T> Stream<T> iterate(T seed, Function<? super T, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return Stream.ofAll(Iterator.iterate(seed, f));
     }
 
@@ -248,7 +246,6 @@ public static <T> Stream<T> iterate(T seed, Function<? super T, ? extends T> f)
      * @return A new Stream
      */
     public static <T> Stream<T> iterate(Supplier<? extends Option<? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return Stream.ofAll(Iterator.iterate(supplier));
     }
 
@@ -262,7 +259,6 @@ public static <T> Stream<T> iterate(Supplier<? extends Option<? extends T>> supp
      */
     @SuppressWarnings("unchecked")
     public static <T> Stream<T> cons(T head, Supplier<? extends Stream<? extends T>> tailSupplier) {
-        Objects.requireNonNull(tailSupplier, "tailSupplier is null");
         return new ConsImpl<>(head, (Supplier<Stream<T>>) tailSupplier);
     }
 
@@ -317,7 +313,6 @@ public static <T> Stream<T> of(T element) {
      */
     @SafeVarargs
     public static <T> Stream<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(new Iterator<T>() {
             int i = 0;
 
@@ -344,7 +339,6 @@ public T next() {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> Stream<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return Stream.ofAll(io.vavr.collection.Collections.tabulate(n, f));
     }
 
@@ -358,7 +352,6 @@ public static <T> Stream<T> tabulate(int n, Function<? super Integer, ? extends
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> Stream<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return Stream.ofAll(io.vavr.collection.Collections.fill(n, s));
     }
 
@@ -383,7 +376,6 @@ public static <T> Stream<T> fill(int n, T element) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Stream<T> ofAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof Stream) {
             return (Stream<T>) elements;
         } else if (elements instanceof ListView
@@ -402,7 +394,6 @@ public static <T> Stream<T> ofAll(Iterable<? extends T> elements) {
      * @return A Stream containing the given elements in the same order.
      */
     public static <T> Stream<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return StreamFactory.create(javaStream.iterator());
     }
 
@@ -414,7 +405,6 @@ public static <T> Stream<T> ofAll(java.util.stream.Stream<? extends T> javaStrea
      * @throws NullPointerException if elements is null
      */
     public static Stream<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -426,7 +416,6 @@ public static Stream<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -438,7 +427,6 @@ public static Stream<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -450,7 +438,6 @@ public static Stream<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -462,7 +449,6 @@ public static Stream<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -474,7 +460,6 @@ public static Stream<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -486,7 +471,6 @@ public static Stream<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -498,7 +482,6 @@ public static Stream<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Stream<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return Stream.ofAll(Iterator.ofAll(elements));
     }
 
@@ -851,7 +834,6 @@ public static <T> Stream<T> continually(T t) {
      * @return a new Stream
      */
     public final Stream<T> appendSelf(Function<? super Stream<T>, ? extends Stream<T>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? this : new AppendSelf<>((Cons<T>) this, mapper).stream();
     }
 
@@ -967,7 +949,6 @@ public final Stream<T> distinct() {
 
     @Override
     public final Stream<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final java.util.Set<T> seen = new java.util.TreeSet<>(comparator);
         return filter(seen::add);
     }
@@ -989,13 +970,11 @@ public final Stream<T> drop(int n) {
 
     @Override
     public final Stream<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public final Stream<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         Stream<T> stream = this;
         while (!stream.isEmpty() && predicate.test(stream.head())) {
             stream = stream.tail();
@@ -1014,19 +993,16 @@ public final Stream<T> dropRight(int n) {
 
     @Override
     public final Stream<T> dropRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return reverse().dropUntil(predicate).reverse();
     }
 
     @Override
     public final Stream<T> dropRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
     @Override
     public final Stream<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -1042,13 +1018,11 @@ public final Stream<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public final Stream<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Collections.filterNot(this, predicate);
     }
 
     @Override
     public final <U> Stream<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? Empty.instance() : Stream.ofAll(new FlatMapIterator<>(this.iterator(), mapper));
     }
 
@@ -1160,7 +1134,6 @@ public final Stream<T> insert(int index, T element) {
 
     @Override
     public final Stream<T> insertAll(int index, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (index < 0) {
             throw new IndexOutOfBoundsException("insertAll(" + index + ", elements)");
         } else if (index == 0) {
@@ -1239,7 +1212,6 @@ public boolean isDefinedAt(Integer index) {
 
     @Override
     public final <U> Stream<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return Empty.instance();
         } else {
@@ -1290,13 +1262,14 @@ public final Stream<T> patch(int from, Iterable<? extends T> that, int replaced)
 
     @Override
     public final Tuple2<Stream<T>, Stream<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
+        if (isEmpty()) {
+            return Tuple.of(empty(), empty());
+        }
         return Tuple.of(filter(predicate), filter(predicate.negate()));
     }
 
     @Override
     public final Stream<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -1331,7 +1304,6 @@ public final Stream<T> prepend(T element) {
 
     @Override
     public final Stream<T> prependAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty()) {
             if (elements instanceof Stream) {
                 @SuppressWarnings("unchecked")
@@ -1357,7 +1329,6 @@ public final Stream<T> remove(T element) {
 
     @Override
     public final Stream<T> removeFirst(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -1502,7 +1473,6 @@ public final Stream<T> sorted() {
 
     @Override
     public final Stream<T> sorted(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : toJavaStream().sorted(comparator).collect(Stream.collector());
     }
 
@@ -1518,7 +1488,6 @@ public final <U> Stream<T> sortBy(Comparator<? super U> comparator, Function<? s
 
     @Override
     public final Tuple2<Stream<T>, Stream<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Tuple.of(takeWhile(predicate), dropWhile(predicate));
     }
 
@@ -1529,7 +1498,6 @@ public final Tuple2<Stream<T>, Stream<T>> splitAt(int n) {
 
     @Override
     public final Tuple2<Stream<T>, Stream<T>> splitAt(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Tuple.of(takeWhile(predicate.negate()), dropWhile(predicate.negate()));
     }
 
@@ -1602,13 +1570,11 @@ public final Stream<T> take(int n) {
 
     @Override
     public final Stream<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeWhile(predicate.negate());
     }
 
     @Override
     public final Stream<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Empty.instance();
         } else {
@@ -1634,13 +1600,11 @@ public final Stream<T> takeRight(int n) {
 
     @Override
     public final Stream<T> takeRightUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return reverse().takeUntil(predicate).reverse();
     }
 
     @Override
     public final Stream<T> takeRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightUntil(predicate.negate());
     }
 
@@ -1653,7 +1617,6 @@ public final Stream<T> takeRightWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Stream<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1682,7 +1645,6 @@ public final Stream<T> update(int index, T element) {
 
     @Override
     public final Stream<T> update(int index, Function<? super T, ? extends T> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         return update(index, updater.apply(get(index)));
     }
 
@@ -1693,14 +1655,11 @@ public final <U> Stream<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public final <U, R> Stream<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public final <U> Stream<Tuple2<T, U>> zipAll(Iterable<? extends U> iterable, T thisElem, U thatElem) {
-        Objects.requireNonNull(iterable, "iterable is null");
         return Stream.ofAll(iterator().zipAll(iterable, thisElem, thatElem));
     }
 
@@ -1711,7 +1670,6 @@ public final Stream<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public final <U> Stream<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWithIndex(mapper));
     }
 
@@ -1732,7 +1690,6 @@ public final Stream<T> extend(T next) {
      * @return new {@code Stream} composed from this stream extended with values provided by the supplier
      */
     public final Stream<T> extend(Supplier<? extends T> nextSupplier) {
-        Objects.requireNonNull(nextSupplier, "nextSupplier is null");
         return Stream.ofAll(appendAll(Stream.continually(nextSupplier)));
     }
 
@@ -1744,7 +1701,6 @@ public final Stream<T> extend(Supplier<? extends T> nextSupplier) {
      * @return new {@code Stream} composed from this stream extended with values calculated by the provided function
      */
     public final Stream<T> extend(Function<? super T, ? extends T> nextFunction) {
-        Objects.requireNonNull(nextFunction, "nextFunction is null");
         if (isEmpty()) {
             return this;
         } else {
@@ -1801,7 +1757,6 @@ public Stream<T> append(T element) {
 
         @Override
         public Stream<T> appendAll(Iterable<? extends T> elements) {
-            Objects.requireNonNull(elements, "elements is null");
             if (Collections.isEmpty(elements)) {
                 return this;
             } else {
@@ -1881,7 +1836,6 @@ public static abstract class Cons<T> extends Stream<T> {
         final Lazy<Stream<T>> tail;
 
         Cons(T head, Supplier<Stream<T>> tail) {
-            Objects.requireNonNull(tail, "tail is null");
             this.head = head;
             this.tail = Lazy.of(tail);
         }
@@ -1947,7 +1901,6 @@ public Stream<T> append(T element) {
 
         @Override
         public Stream<T> appendAll(Iterable<? extends T> elements) {
-            Objects.requireNonNull(elements, "elements is null");
             if (Collections.isEmpty(elements)) {
                 return this;
             } else {
@@ -1987,7 +1940,6 @@ public Stream<T> append(T element) {
 
         @Override
         public Stream<T> appendAll(Iterable<? extends T> elements) {
-            Objects.requireNonNull(elements, "elements is null");
             return new AppendElements<>(head, queue.appendAll(elements), tail);
         }
 
diff --git a/src/main/java/io/vavr/collection/Traversable.java b/src/main/java/io/vavr/collection/Traversable.java
index 70ae8e541..1d7b5f1fb 100644
--- a/src/main/java/io/vavr/collection/Traversable.java
+++ b/src/main/java/io/vavr/collection/Traversable.java
@@ -269,7 +269,6 @@ default Option<Double> average() {
      * @throws NullPointerException if {@code elements} is null
      */
     default boolean containsAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         for (T element : elements) {
             if (!contains(element)) {
                 return false;
@@ -286,7 +285,6 @@ default boolean containsAll(Iterable<? extends T> elements) {
      * @throws NullPointerException if {@code predicate} is null.
      */
     default int count(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return foldLeft(0, (i, t) -> predicate.test(t) ? i + 1 : i);
     }
 
@@ -411,7 +409,6 @@ default int count(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default boolean existsUnique(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         boolean exists = false;
         for (T t : this) {
             if (predicate.test(t)) {
@@ -446,7 +443,6 @@ default boolean existsUnique(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default Traversable<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
@@ -458,7 +454,6 @@ default Traversable<T> filterNot(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default Option<T> find(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (T a : this) {
             if (predicate.test(a)) {
                 return Option.some(a); // may be Some(null)
@@ -477,7 +472,6 @@ default Option<T> find(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default Option<T> findLast(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return iterator().findLast(predicate);
     }
 
@@ -525,7 +519,6 @@ default Option<T> findLast(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code combine} is null
      */
     default T fold(T zero, BiFunction<? super T, ? super T, ? extends T> combine) {
-        Objects.requireNonNull(combine, "combine is null");
         return foldLeft(zero, combine);
     }
 
@@ -547,7 +540,6 @@ default T fold(T zero, BiFunction<? super T, ? super T, ? extends T> combine) {
      */
     @Override
     default <U> U foldLeft(U zero, BiFunction<? super U, ? super T, ? extends U> combine) {
-        Objects.requireNonNull(combine, "combine is null");
         U xs = zero;
         for (T x : this) {
             xs = combine.apply(xs, x);
@@ -590,7 +582,6 @@ default <U> U foldLeft(U zero, BiFunction<? super U, ? super T, ? extends U> com
      * @throws NullPointerException if {@code action} is null
      */
     default void forEachWithIndex(ObjIntConsumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         int index = 0;
         for (T t : this) {
             action.accept(t, index++);
@@ -921,7 +912,6 @@ default Option<T> max() {
      * @throws NullPointerException if {@code comparator} is null
      */
     default Option<T> maxBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         if (isEmpty()) {
             return Option.none();
         } else {
@@ -939,7 +929,6 @@ default Option<T> maxBy(Comparator<? super T> comparator) {
      * @throws NullPointerException if {@code f} is null.
      */
     default <U extends Comparable<? super U>> Option<T> maxBy(Function<? super T, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isEmpty()) {
             return Option.none();
         } else {
@@ -1006,10 +995,9 @@ default Option<T> min() {
      *
      * @param comparator A non-null element comparator
      * @return {@code Some(minimum)} of this elements or {@code None} if this is empty
-     * @throws NullPointerException if {@code comparator} is null
+     * @throws NullPointerException if {@code comparator} is null, unless no comparison is needed.
      */
     default Option<T> minBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         if (isEmpty()) {
             return Option.none();
         } else {
@@ -1027,7 +1015,6 @@ default Option<T> minBy(Comparator<? super T> comparator) {
      * @throws NullPointerException if {@code f} is null.
      */
     default <U extends Comparable<? super U>> Option<T> minBy(Function<? super T, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isEmpty()) {
             return Option.none();
         } else {
@@ -1214,7 +1201,6 @@ default Number product() {
      * @throws NullPointerException   if {@code op} is null
      */
     default T reduce(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return reduceLeft(op);
     }
 
@@ -1227,7 +1213,6 @@ default T reduce(BiFunction<? super T, ? super T, ? extends T> op) {
      * @throws NullPointerException if {@code op} is null
      */
     default Option<T> reduceOption(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return reduceLeftOption(op);
     }
 
@@ -1240,7 +1225,6 @@ default Option<T> reduceOption(BiFunction<? super T, ? super T, ? extends T> op)
      * @throws NullPointerException   if {@code op} is null
      */
     default T reduceLeft(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return iterator().reduceLeft(op);
     }
 
@@ -1254,7 +1238,6 @@ default T reduceLeft(BiFunction<? super T, ? super T, ? extends T> op) {
      * @throws NullPointerException if {@code op} is null
      */
     default Option<T> reduceLeftOption(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return isEmpty() ? Option.none() : Option.some(reduceLeft(op));
     }
 
@@ -1267,7 +1250,6 @@ default Option<T> reduceLeftOption(BiFunction<? super T, ? super T, ? extends T>
      * @throws NullPointerException   if {@code op} is null
      */
     default T reduceRight(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         if (isEmpty()) {
             throw new NoSuchElementException("reduceRight on empty");
         } else {
@@ -1285,7 +1267,6 @@ default T reduceRight(BiFunction<? super T, ? super T, ? extends T> op) {
      * @throws NullPointerException if {@code op} is null
      */
     default Option<T> reduceRightOption(BiFunction<? super T, ? super T, ? extends T> op) {
-        Objects.requireNonNull(op, "op is null");
         return isEmpty() ? Option.none() : Option.some(reduceRight(op));
     }
 
@@ -1603,8 +1584,6 @@ default Number sum() {
      */
     default <T1, T2> Tuple2<Iterator<T1>, Iterator<T2>> unzip(
             Function<? super T, ? extends T1> unzipper1, Function<? super T, ? extends T2> unzipper2) {
-        Objects.requireNonNull(unzipper1, "unzipper1 is null");
-        Objects.requireNonNull(unzipper2, "unzipper2 is null");
         final Iterator<T1> iter1 = iterator().map(unzipper1);
         final Iterator<T2> iter2 = iterator().map(unzipper2);
         return Tuple.of(iter1, iter2);
@@ -1626,9 +1605,6 @@ default <T1, T2, T3> Tuple3<Iterator<T1>, Iterator<T2>, Iterator<T3>> unzip3(
             Function<? super T, ? extends T1> unzipper1,
             Function<? super T, ? extends T2> unzipper2,
             Function<? super T, ? extends T3> unzipper3) {
-        Objects.requireNonNull(unzipper1, "unzipper1 is null");
-        Objects.requireNonNull(unzipper2, "unzipper2 is null");
-        Objects.requireNonNull(unzipper2, "unzipper3 is null");
         final Iterator<T1> iter1 = iterator().map(unzipper1);
         final Iterator<T2> iter2 = iterator().map(unzipper2);
         final Iterator<T3> iter3 = iterator().map(unzipper3);
@@ -1723,7 +1699,6 @@ default <K, V> SortedMap<K, V> toSortedMap(
             Function<? super T, ? extends K> keyMapper,
             Function<? super T, ? extends V> valueMapper,
             BiFunction<? super V, ? super V, ? extends V> merge) {
-        Objects.requireNonNull(keyComparator, "keyComparator is null");
         if (isEmpty()) {
             return TreeMap.empty(keyComparator);
         }
@@ -1786,9 +1761,6 @@ default <K, V> Map<K, V> toMap(
             Function<? super T, ? extends K> keyMapper,
             Function<? super T, ? extends V> valueMapper,
             BiFunction<? super V, ? super V, ? extends V> merge) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
-        Objects.requireNonNull(merge, "merge is null");
         if (isEmpty()) {
             return HashMap.empty();
         }
diff --git a/src/main/java/io/vavr/collection/Tree.java b/src/main/java/io/vavr/collection/Tree.java
index 919a7b5d3..b0aa721e5 100644
--- a/src/main/java/io/vavr/collection/Tree.java
+++ b/src/main/java/io/vavr/collection/Tree.java
@@ -106,7 +106,6 @@ public static <T> Node<T> of(T value) {
     @SuppressWarnings("varargs")
     @SafeVarargs
     public static <T> Node<T> of(T value, Node<T>... children) {
-        Objects.requireNonNull(children, "children is null");
         return new Node<>(value, io.vavr.collection.List.of(children));
     }
 
@@ -119,7 +118,6 @@ public static <T> Node<T> of(T value, Node<T>... children) {
      * @return A new Node instance.
      */
     public static <T> Node<T> of(T value, Iterable<Node<T>> children) {
-        Objects.requireNonNull(children, "children is null");
         return new Node<>(value, io.vavr.collection.List.ofAll(children));
     }
 
@@ -134,7 +132,6 @@ public static <T> Node<T> of(T value, Iterable<Node<T>> children) {
     @SuppressWarnings("varargs")
     @SafeVarargs
     public static <T> Tree<T> of(T... values) {
-        Objects.requireNonNull(values, "values is null");
         final io.vavr.collection.List<T> list = io.vavr.collection.List.of(values);
         return list.isEmpty() ? Empty.instance() : new Node<>(list.head(), list.tail().map(Tree::of));
     }
@@ -152,7 +149,6 @@ public static <T> Tree<T> of(T... values) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Tree<T> ofAll(Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable, "iterable is null");
         if (iterable instanceof Tree) {
             return (Tree<T>) iterable;
         } else {
@@ -169,7 +165,6 @@ public static <T> Tree<T> ofAll(Iterable<? extends T> iterable) {
      * @return A Tree containing the given elements in the same order.
      */
     public static <T> Tree<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return ofAll(io.vavr.collection.Iterator.ofAll(javaStream.iterator()));
     }
 
@@ -184,7 +179,6 @@ public static <T> Tree<T> ofAll(java.util.stream.Stream<? extends T> javaStream)
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> Tree<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return io.vavr.collection.Collections.tabulate(n, f, empty(), Tree::of);
     }
 
@@ -198,7 +192,6 @@ public static <T> Tree<T> tabulate(int n, Function<? super Integer, ? extends T>
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> Tree<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return io.vavr.collection.Collections.fill(n, s, empty(), Tree::of);
     }
 
@@ -241,7 +234,6 @@ public static <T> Tree<T> fill(int n, T element) {
      * @throws NullPointerException if {@code descend} is null
      */
     public static <T> Node<T> recurse(T seed, Function<? super T, ? extends Iterable<? extends T>> descend) {
-        Objects.requireNonNull(descend, "descend is null");
         return Tree.of(seed, Stream.of(seed).flatMap(descend).map(children -> recurse(children, descend)));
     }
 
@@ -271,9 +263,6 @@ public static <T> Node<T> recurse(T seed, Function<? super T, ? extends Iterable
      * @throws NullPointerException if {@code source}, {@code idMapper} or {@code parentMapper} is null
      */
     public static <T, ID> List<Node<T>> build(Iterable<? extends T> source, Function<? super T, ? extends ID> idMapper, Function<? super T, ? extends ID> parentMapper) {
-        Objects.requireNonNull(source, "source is null");
-        Objects.requireNonNull(source, "idMapper is null");
-        Objects.requireNonNull(source, "parentMapper is null");
         final List<T> list = List.ofAll(source);
         final Map<ID, List<T>> byParent = list.groupBy(parentMapper);
         final Function<? super T, Iterable<? extends T>> descend = idMapper
@@ -377,7 +366,6 @@ public final io.vavr.collection.Iterator<T> iterator(Order order) {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Tree<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -398,7 +386,6 @@ public final Seq<Node<T>> traverse() {
      * @throws java.lang.NullPointerException if order is null
      */
     public final Seq<Node<T>> traverse(Order order) {
-        Objects.requireNonNull(order, "order is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -486,7 +473,6 @@ public final Seq<T> distinct() {
 
     @Override
     public final Seq<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -496,7 +482,6 @@ public final Seq<T> distinctBy(Comparator<? super T> comparator) {
 
     @Override
     public final <U> Seq<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -524,13 +509,11 @@ public final Seq<T> dropRight(int n) {
 
     @Override
     public final Seq<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public final Seq<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -540,7 +523,6 @@ public final Seq<T> dropWhile(Predicate<? super T> predicate) {
 
     @Override
     public final Seq<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -550,7 +532,6 @@ public final Seq<T> filter(Predicate<? super T> predicate) {
 
     @Override
     public final Seq<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Stream.empty();
         } else {
@@ -560,13 +541,11 @@ public final Seq<T> filterNot(Predicate<? super T> predicate) {
 
     @Override
     public final <U> Tree<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? Empty.instance() : Tree.flatMap((Node<T>) this, mapper);
     }
 
     @Override
     public final <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isEmpty()) {
             return zero;
         } else {
@@ -625,7 +604,6 @@ public final io.vavr.collection.Iterator<T> iterator() {
 
     @Override
     public final <U> Tree<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? Empty.instance() : Tree.map((Node<T>) this, mapper);
     }
 
@@ -642,7 +620,6 @@ public final Tree<T> orElse(Supplier<? extends Iterable<? extends T>> supplier)
     @SuppressWarnings("unchecked")
     @Override
     public final Tuple2<Seq<T>, Seq<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Tuple.of(Stream.empty(), Stream.empty());
         } else {
@@ -652,7 +629,6 @@ public final Tuple2<Seq<T>, Seq<T>> partition(Predicate<? super T> predicate) {
 
     @Override
     public final Tree<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -675,7 +651,6 @@ public final Tree<T> replaceAll(T currentElement, T newElement) {
 
     @Override
     public final Seq<T> retainAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return values().retainAll(elements);
     }
 
@@ -712,7 +687,6 @@ public final io.vavr.collection.Iterator<Seq<T>> sliding(int size, int step) {
     @SuppressWarnings("unchecked")
     @Override
     public final Tuple2<Seq<T>, Seq<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         if (isEmpty()) {
             return Tuple.of(Stream.empty(), Stream.empty());
         } else {
@@ -759,13 +733,11 @@ public final Seq<T> takeRight(int n) {
 
     @Override
     public final Seq<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return values().takeUntil(predicate);
     }
 
     @Override
     public final Seq<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return values().takeWhile(predicate);
     }
 
@@ -776,8 +748,6 @@ public final <U> Tree<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public final <U, R> Tree<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isEmpty()) {
             return Empty.instance();
         } else {
@@ -787,7 +757,6 @@ public final <U, R> Tree<R> zipWith(Iterable<? extends U> that, BiFunction<? sup
 
     @Override
     public final <U> Tree<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         if (isEmpty()) {
             return io.vavr.collection.Iterator.<U>ofAll(that).map(elem -> Tuple.of(thisElem, elem)).toTree();
         } else {
@@ -811,7 +780,6 @@ public final Tree<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public final <U> Tree<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return zipWith(io.vavr.collection.Iterator.from(0), mapper);
     }
 
@@ -847,7 +815,6 @@ public static final class Node<T> extends Tree<T> implements Serializable {
          * @throws IllegalArgumentException if children is empty
          */
         public Node(T value, io.vavr.collection.List<Node<T>> children) {
-            Objects.requireNonNull(children, "children is null");
             this.value = value;
             this.children = children;
             this.size = children.foldLeft(1, (acc, child) -> acc + child.size);
diff --git a/src/main/java/io/vavr/collection/TreeMap.java b/src/main/java/io/vavr/collection/TreeMap.java
index 5ae1b1556..f8680dd36 100644
--- a/src/main/java/io/vavr/collection/TreeMap.java
+++ b/src/main/java/io/vavr/collection/TreeMap.java
@@ -98,8 +98,6 @@ public static <K, V> Collector<Tuple2<K, V>, ArrayList<Tuple2<K, V>>, TreeMap<K,
      */
     public static <K extends Comparable<? super K>, V, T extends V> Collector<T, ArrayList<T>, TreeMap<K, V>> collector(
             Function<? super T, ? extends K> keyMapper) {
-        Objects.requireNonNull(keyMapper, "key comparator is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return createCollector(EntryComparator.natural(), keyMapper, v -> v);
     }
 
@@ -119,9 +117,6 @@ public static <K extends Comparable<? super K>, V, T extends V> Collector<T, Arr
     public static <K extends Comparable<? super K>, V, T> Collector<T, ArrayList<T>, TreeMap<K, V>> collector(
             Function<? super T, ? extends K> keyMapper,
             Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "key comparator is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return createCollector(EntryComparator.natural(), keyMapper, valueMapper);
     }
 
@@ -139,8 +134,6 @@ public static <K extends Comparable<? super K>, V, T> Collector<T, ArrayList<T>,
     public static <K, V, T extends V> Collector<T, ArrayList<T>, TreeMap<K, V>> collector(
             Comparator<? super K> keyComparator,
             Function<? super T, ? extends K> keyMapper) {
-        Objects.requireNonNull(keyMapper, "key comparator is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return createCollector(EntryComparator.of(keyComparator), keyMapper, v -> v);
     }
 
@@ -159,9 +152,6 @@ public static <K, V, T extends V> Collector<T, ArrayList<T>, TreeMap<K, V>> coll
     public static <K, V, T> Collector<T, ArrayList<T>, TreeMap<K, V>> collector(
             Comparator<? super K> keyComparator,
             Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends V> valueMapper) {
-        Objects.requireNonNull(keyMapper, "key comparator is null");
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return createCollector(EntryComparator.of(keyComparator), keyMapper, valueMapper);
     }
 
@@ -215,7 +205,6 @@ public static <K, V> TreeMap<K, V> narrow(TreeMap<? extends K, ? extends V> tree
      * @return A new TreeMap containing the given entry.
      */
     public static <K extends Comparable<? super K>, V> TreeMap<K, V> of(Tuple2<? extends K, ? extends V> entry) {
-        Objects.requireNonNull(entry, "entry is null");
         return createFromTuple(EntryComparator.natural(), entry);
     }
 
@@ -229,7 +218,6 @@ public static <K extends Comparable<? super K>, V> TreeMap<K, V> of(Tuple2<? ext
      * @return A new TreeMap containing the given entry.
      */
     public static <K, V> TreeMap<K, V> of(Comparator<? super K> keyComparator, Tuple2<? extends K, ? extends V> entry) {
-        Objects.requireNonNull(entry, "entry is null");
         return createFromTuple(EntryComparator.of(keyComparator), entry);
     }
 
@@ -242,7 +230,6 @@ public static <K, V> TreeMap<K, V> of(Comparator<? super K> keyComparator, Tuple
      * @return A new Map containing the given map
      */
     public static <K extends Comparable<? super K>, V> TreeMap<K, V> ofAll(java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         return createFromMap(EntryComparator.natural(), map);
     }
 
@@ -324,7 +311,6 @@ public static <T, K, V> TreeMap<K, V> ofAll(Comparator<? super K> keyComparator,
      * @return A new Map containing the given map
      */
     public static <K, V> TreeMap<K, V> ofAll(Comparator<? super K> keyComparator, java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         return createFromMap(EntryComparator.of(keyComparator), map);
     }
 
@@ -791,7 +777,6 @@ public static <K, V> TreeMap<K, V> of(Comparator<? super K> keyComparator, K k1,
      * @throws NullPointerException if {@code keyComparator} or {@code f} are null
      */
     public static <K, V> TreeMap<K, V> tabulate(Comparator<? super K> keyComparator, int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         return createTreeMap(EntryComparator.of(keyComparator), Collections.tabulate(n, f));
     }
 
@@ -808,7 +793,6 @@ public static <K, V> TreeMap<K, V> tabulate(Comparator<? super K> keyComparator,
      * @throws NullPointerException if {@code f} is null
      */
     public static <K extends Comparable<? super K>, V> TreeMap<K, V> tabulate(int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V>> f) {
-        Objects.requireNonNull(f, "f is null");
         return createTreeMap(EntryComparator.natural(), Collections.tabulate(n, f));
     }
 
@@ -825,7 +809,6 @@ public static <K extends Comparable<? super K>, V> TreeMap<K, V> tabulate(int n,
      */
     @SuppressWarnings("unchecked")
     public static <K, V> TreeMap<K, V> fill(Comparator<? super K> keyComparator, int n, Supplier<? extends Tuple2<? extends K, ? extends V>> s) {
-        Objects.requireNonNull(s, "s is null");
         return createTreeMap(EntryComparator.of(keyComparator), Collections.fill(n, s));
     }
 
@@ -841,7 +824,6 @@ public static <K, V> TreeMap<K, V> fill(Comparator<? super K> keyComparator, int
      * @throws NullPointerException if {@code s} is null
      */
     public static <K extends Comparable<? super K>, V> TreeMap<K, V> fill(int n, Supplier<? extends Tuple2<? extends K, ? extends V>> s) {
-        Objects.requireNonNull(s, "s is null");
         return createTreeMap(EntryComparator.natural(), Collections.fill(n, s));
     }
 
@@ -1140,13 +1122,11 @@ public <K2, V2> TreeMap<K2, V2> map(BiFunction<? super K, ? super V, Tuple2<K2,
     @Override
     public <K2, V2> TreeMap<K2, V2> map(Comparator<? super K2> keyComparator,
             BiFunction<? super K, ? super V, Tuple2<K2, V2>> mapper) {
-        Objects.requireNonNull(keyComparator, "keyComparator is null");
         return map(this, EntryComparator.of(keyComparator), mapper);
     }
 
     @Override
     public <K2> TreeMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
         return map((k, v) -> Tuple.of(keyMapper.apply(k), v));
     }
 
@@ -1158,7 +1138,6 @@ public <K2> TreeMap<K2, V> mapKeys(Function<? super K, ? extends K2> keyMapper,
 
     @Override
     public <W> TreeMap<K, W> mapValues(Function<? super V, ? extends W> valueMapper) {
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return map(comparator(), (k, v) -> Tuple.of(k, valueMapper.apply(v)));
     }
 
@@ -1285,7 +1264,6 @@ public TreeMap<K, V> replaceAll(BiFunction<? super K, ? super V, ? extends V> fu
 
     @Override
     public TreeMap<K, V> retainAll(Iterable<? extends Tuple2<K, V>> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(entries.comparator());
         for (Tuple2<K, V> entry : elements) {
             if (contains(entry)) {
@@ -1398,20 +1376,16 @@ public String toString() {
 
     private static <K, K2, V, V2> TreeMap<K2, V2> bimap(TreeMap<K, V> map, EntryComparator<K2, V2> entryComparator,
             Function<? super K, ? extends K2> keyMapper, Function<? super V, ? extends V2> valueMapper) {
-        Objects.requireNonNull(keyMapper, "keyMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         return createTreeMap(entryComparator, map.entries, entry -> entry.map(keyMapper, valueMapper));
     }
 
     private static <K, V, K2, V2> TreeMap<K2, V2> flatMap(TreeMap<K, V> map, EntryComparator<K2, V2> entryComparator,
             BiFunction<? super K, ? super V, ? extends Iterable<Tuple2<K2, V2>>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return createTreeMap(entryComparator, map.entries.iterator().flatMap(entry -> mapper.apply(entry._1, entry._2)));
     }
 
     private static <K, K2, V, V2> TreeMap<K2, V2> map(TreeMap<K, V> map, EntryComparator<K2, V2> entryComparator,
             BiFunction<? super K, ? super V, Tuple2<K2, V2>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return createTreeMap(entryComparator, map.entries, entry -> entry.map(mapper));
     }
 
@@ -1431,7 +1405,6 @@ private static <K, V, T> Collector<T, ArrayList<T>, TreeMap<K, V>> createCollect
     @SuppressWarnings("unchecked")
     private static <K, V> TreeMap<K, V> createTreeMap(EntryComparator<K, V> entryComparator,
             Iterable<? extends Tuple2<? extends K, ? extends V>> entries) {
-        Objects.requireNonNull(entries, "entries is null");
         RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(entryComparator);
         for (Tuple2<K, V> entry : (Iterable<Tuple2<K, V>>) entries) {
             tree = tree.insert(entry);
@@ -1450,7 +1423,6 @@ private static <K, K2, V, V2> TreeMap<K2, V2> createTreeMap(EntryComparator<K2,
 
     @SuppressWarnings("unchecked")
     private static <K, V> TreeMap<K, V> createFromMap(EntryComparator<K, V> entryComparator, java.util.Map<? extends K, ? extends V> map) {
-        Objects.requireNonNull(map, "map is null");
         RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(entryComparator);
         for (java.util.Map.Entry<K, V> entry : ((java.util.Map<K, V>) map).entrySet()) {
             tree = tree.insert(Tuple.of(entry.getKey(), entry.getValue()));
@@ -1460,13 +1432,11 @@ private static <K, V> TreeMap<K, V> createFromMap(EntryComparator<K, V> entryCom
 
     @SuppressWarnings("unchecked")
     private static <K, V> TreeMap<K, V> createFromTuple(EntryComparator<K, V> entryComparator, Tuple2<? extends K, ? extends V> entry) {
-        Objects.requireNonNull(entry, "entry is null");
         return new TreeMap<>(RedBlackTree.of(entryComparator, (Tuple2<K, V>) entry));
     }
 
     @SuppressWarnings("unchecked")
     private static <K, V> TreeMap<K, V> createFromTuples(EntryComparator<K, V> entryComparator, Tuple2<? extends K, ? extends V>... entries) {
-        Objects.requireNonNull(entries, "entries is null");
         RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(entryComparator);
         for (Tuple2<? extends K, ? extends V> entry : entries) {
             tree = tree.insert((Tuple2<K, V>) entry);
@@ -1476,7 +1446,6 @@ private static <K, V> TreeMap<K, V> createFromTuples(EntryComparator<K, V> entry
 
     @SafeVarargs
     private static <K, V> TreeMap<K, V> createFromMapEntries(EntryComparator<K, V> entryComparator, java.util.Map.Entry<? extends K, ? extends V>... entries) {
-        Objects.requireNonNull(entries, "entries is null");
         RedBlackTree<Tuple2<K, V>> tree = RedBlackTree.empty(entryComparator);
         for (java.util.Map.Entry<? extends K, ? extends V> entry : entries) {
             final K key = entry.getKey();
@@ -1517,7 +1486,6 @@ private interface EntryComparator<K, V> extends Comparator<Tuple2<K, V>>, Serial
         long serialVersionUID = 1L;
 
         static <K, V> EntryComparator<K, V> of(Comparator<? super K> keyComparator) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
             return new Specific<>(keyComparator);
         }
 
diff --git a/src/main/java/io/vavr/collection/TreeMultimap.java b/src/main/java/io/vavr/collection/TreeMultimap.java
index e3da5b05d..caa6332ca 100644
--- a/src/main/java/io/vavr/collection/TreeMultimap.java
+++ b/src/main/java/io/vavr/collection/TreeMultimap.java
@@ -97,7 +97,6 @@ public <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2> empty
          * @return A new empty TreeMultimap.
          */
         public <K, V2 extends V> TreeMultimap<K, V2> empty(Comparator<? super K> keyComparator) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
             return new TreeMultimap<>(TreeMap.empty(keyComparator), containerType, emptyContainer);
         }
 
@@ -124,8 +123,6 @@ public <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2> ofEnt
          * @return A new TreeMultimap containing the given entries.
          */
         public <K, V2 extends V> TreeMultimap<K, V2> ofEntries(Comparator<? super K> keyComparator, Iterable<? extends Tuple2<? extends K, ? extends V2>> entries) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
-            Objects.requireNonNull(entries, "entries is null");
             TreeMultimap<K, V2> result = empty(keyComparator);
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -160,8 +157,6 @@ public final <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2>
         @SuppressWarnings({ "unchecked", "varargs" })
         @SafeVarargs
         public final <K, V2 extends V> TreeMultimap<K, V2> ofEntries(Comparator<? super K> keyComparator, Tuple2<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
-            Objects.requireNonNull(entries, "entries is null");
             TreeMultimap<K, V2> result = empty(keyComparator);
             for (Tuple2<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry._1, entry._2);
@@ -196,8 +191,6 @@ public final <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2>
         @SuppressWarnings({ "unchecked", "varargs" })
         @SafeVarargs
         public final <K, V2 extends V> TreeMultimap<K, V2> ofEntries(Comparator<? super K> keyComparator, java.util.Map.Entry<? extends K, ? extends V2>... entries) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
-            Objects.requireNonNull(entries, "entries is null");
             TreeMultimap<K, V2> result = empty(keyComparator);
             for (java.util.Map.Entry<? extends K, ? extends V2> entry : entries) {
                 result = result.put(entry.getKey(), entry.getValue());
@@ -329,8 +322,6 @@ public <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2> tabul
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> TreeMultimap<K, V2> tabulate(Comparator<? super K> keyComparator, int n, Function<? super Integer, ? extends Tuple2<? extends K, ? extends V2>> f) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
-            Objects.requireNonNull(f, "f is null");
             return ofEntries(keyComparator, Collections.tabulate(n, (Function<? super Integer, ? extends Tuple2<K, V2>>) f));
         }
 
@@ -363,8 +354,6 @@ public <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2> fill(
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> TreeMultimap<K, V2> fill(Comparator<? super K> keyComparator, int n, Supplier<? extends Tuple2<? extends K, ? extends V2>> s) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
-            Objects.requireNonNull(s, "s is null");
             return ofEntries(keyComparator, Collections.fill(n, (Supplier<? extends Tuple2<K, V2>>) s));
         }
 
@@ -395,7 +384,6 @@ public <K extends Comparable<? super K>, V2 extends V> TreeMultimap<K, V2> fill(
          */
         @SuppressWarnings("unchecked")
         public <K, V2 extends V> TreeMultimap<K, V2> fill(Comparator<? super K> keyComparator, int n, Tuple2<? extends K, ? extends V2> element) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
             return ofEntries(keyComparator, Collections.fillObject(n, element));
         }
 
@@ -902,7 +890,6 @@ public <K extends Comparable<? super K>, V2 extends V> Collector<Tuple2<K, V2>,
          * @return A {@link TreeMultimap} Collector.
          */
         public <K, V2 extends V> Collector<Tuple2<K, V2>, ArrayList<Tuple2<K, V2>>, TreeMultimap<K, V2>> collector(Comparator<? super K> keyComparator) {
-            Objects.requireNonNull(keyComparator, "keyComparator is null");
             return Collections.toListAndThen(list -> ofEntries(keyComparator, list));
         }
     }
diff --git a/src/main/java/io/vavr/collection/TreeSet.java b/src/main/java/io/vavr/collection/TreeSet.java
index 470ddd4ad..9900c511b 100644
--- a/src/main/java/io/vavr/collection/TreeSet.java
+++ b/src/main/java/io/vavr/collection/TreeSet.java
@@ -76,7 +76,6 @@ public static <T extends Comparable<? super T>> Collector<T, ArrayList<T>, TreeS
      * @return A io.vavr.collection.List Collector.
      */
     public static <T> Collector<T, ArrayList<T>, TreeSet<T>> collector(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return Collections.toListAndThen(list -> TreeSet.ofAll(comparator, list));
     }
 
@@ -85,7 +84,6 @@ public static <T extends Comparable<? super T>> TreeSet<T> empty() {
     }
 
     public static <T> TreeSet<T> empty(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return new TreeSet<>(RedBlackTree.empty(comparator));
     }
 
@@ -110,7 +108,6 @@ public static <T extends Comparable<? super T>> TreeSet<T> of(T value) {
     }
 
     public static <T> TreeSet<T> of(Comparator<? super T> comparator, T value) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return new TreeSet<>(RedBlackTree.of(comparator, value));
     }
 
@@ -123,8 +120,6 @@ public static <T extends Comparable<? super T>> TreeSet<T> of(T... values) {
     @SuppressWarnings("varargs")
     @SafeVarargs
     public static <T> TreeSet<T> of(Comparator<? super T> comparator, T... values) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(values, "values is null");
         return new TreeSet<>(RedBlackTree.of(comparator, values));
     }
 
@@ -140,8 +135,6 @@ public static <T> TreeSet<T> of(Comparator<? super T> comparator, T... values) {
      * @throws NullPointerException if {@code comparator} or {@code f} are null
      */
     public static <T> TreeSet<T> tabulate(Comparator<? super T> comparator, int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(f, "f is null");
         return Collections.tabulate(n, f, TreeSet.empty(comparator), values -> of(comparator, values));
     }
 
@@ -157,7 +150,6 @@ public static <T> TreeSet<T> tabulate(Comparator<? super T> comparator, int n, F
      * @throws NullPointerException if {@code f} is null
      */
     public static <T extends Comparable<? super T>> TreeSet<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return tabulate(Comparators.naturalComparator(), n, f);
     }
 
@@ -172,8 +164,6 @@ public static <T extends Comparable<? super T>> TreeSet<T> tabulate(int n, Funct
      * @throws NullPointerException if {@code comparator} or {@code s} are null
      */
     public static <T> TreeSet<T> fill(Comparator<? super T> comparator, int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(s, "s is null");
         return Collections.fill(n, s, TreeSet.empty(comparator), values -> of(comparator, values));
     }
 
@@ -188,7 +178,6 @@ public static <T> TreeSet<T> fill(Comparator<? super T> comparator, int n, Suppl
      * @throws NullPointerException if {@code s} is null
      */
     public static <T extends Comparable<? super T>> TreeSet<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return fill(Comparators.naturalComparator(), n, s);
     }
 
@@ -198,8 +187,6 @@ public static <T extends Comparable<? super T>> TreeSet<T> ofAll(Iterable<? exte
 
     @SuppressWarnings("unchecked")
     public static <T> TreeSet<T> ofAll(Comparator<? super T> comparator, Iterable<? extends T> values) {
-        Objects.requireNonNull(comparator, "comparator is null");
-        Objects.requireNonNull(values, "values is null");
         if (values instanceof TreeSet && ((TreeSet<?>) values).comparator() == comparator) {
             return (TreeSet<T>) values;
         } else {
@@ -208,12 +195,10 @@ public static <T> TreeSet<T> ofAll(Comparator<? super T> comparator, Iterable<?
     }
 
     public static <T extends Comparable<? super T>> TreeSet<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return ofAll(Iterator.ofAll(javaStream.iterator()));
     }
 
     public static <T> TreeSet<T> ofAll(Comparator<? super T> comparator, java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return ofAll(comparator, Iterator.ofAll(javaStream.iterator()));
     }
 
@@ -225,7 +210,6 @@ public static <T> TreeSet<T> ofAll(Comparator<? super T> comparator, java.util.s
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -237,7 +221,6 @@ public static TreeSet<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -249,7 +232,6 @@ public static TreeSet<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -261,7 +243,6 @@ public static TreeSet<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -273,7 +254,6 @@ public static TreeSet<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -285,7 +265,6 @@ public static TreeSet<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -297,7 +276,6 @@ public static TreeSet<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -309,7 +287,6 @@ public static TreeSet<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static TreeSet<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return TreeSet.ofAll(Iterator.ofAll(elements));
     }
 
@@ -528,7 +505,6 @@ public TreeSet<T> add(T element) {
 
     @Override
     public TreeSet<T> addAll(Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         RedBlackTree<T> that = tree;
         for (T element : elements) {
             if (!that.contains(element)) {
@@ -555,7 +531,6 @@ public Comparator<T> comparator() {
     @SuppressWarnings("unchecked")
     @Override
     public TreeSet<T> diff(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty()) {
             return this;
         } else if (elements instanceof TreeSet) {
@@ -578,13 +553,11 @@ public TreeSet<T> distinct() {
 
     @Override
     public TreeSet<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : TreeSet.ofAll(tree.comparator(), iterator().distinctBy(comparator));
     }
 
     @Override
     public <U> TreeSet<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         return isEmpty() ? this : TreeSet.ofAll(tree.comparator(), iterator().distinctBy(keyExtractor));
     }
 
@@ -612,46 +585,39 @@ public TreeSet<T> dropRight(int n) {
 
     @Override
     public TreeSet<T> dropUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropWhile(predicate.negate());
     }
 
     @Override
     public TreeSet<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final TreeSet<T> treeSet = TreeSet.ofAll(tree.comparator(), iterator().dropWhile(predicate));
         return (treeSet.length() == length()) ? this : treeSet;
     }
 
     @Override
     public TreeSet<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final TreeSet<T> treeSet = TreeSet.ofAll(tree.comparator(), iterator().filter(predicate));
         return (treeSet.length() == length()) ? this : treeSet;
     }
 
     @Override
     public TreeSet<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
     @Override
     public <U> TreeSet<U> flatMap(Comparator<? super U> comparator,
             Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(comparator, iterator().flatMap(mapper));
     }
 
     @Override
     public <U> Set<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? HashSet.empty() : HashSet.ofAll(this).flatMap(mapper);
     }
 
     @Override
     public <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return iterator().foldRight(zero, f);
     }
 
@@ -701,7 +667,6 @@ public Option<TreeSet<T>> initOption() {
     @SuppressWarnings("unchecked")
     @Override
     public TreeSet<T> intersect(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (isEmpty()) {
             return this;
         } else if (elements instanceof TreeSet) {
@@ -763,13 +728,11 @@ public int length() {
 
     @Override
     public <U> TreeSet<U> map(Comparator<? super U> comparator, Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(comparator, iterator().map(mapper));
     }
 
     @Override
     public <U> Set<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? HashSet.empty() : HashSet.ofAll(this).map(mapper);
     }
 
@@ -806,7 +769,6 @@ public Tuple2<TreeSet<T>, TreeSet<T>> partition(Predicate<? super T> predicate)
 
     @Override
     public TreeSet<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -885,7 +847,6 @@ public Iterator<TreeSet<T>> sliding(int size, int step) {
 
     @Override
     public Tuple2<TreeSet<T>, TreeSet<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return iterator().span(predicate).map(i1 -> TreeSet.ofAll(tree.comparator(), i1),
                 i2 -> TreeSet.ofAll(tree.comparator(), i2));
     }
@@ -928,14 +889,12 @@ public TreeSet<T> takeRight(int n) {
 
     @Override
     public TreeSet<T> takeUntil(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final TreeSet<T> treeSet = takeWhile(predicate.negate());
         return (treeSet.length() == length()) ? this : treeSet;
     }
 
     @Override
     public TreeSet<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final TreeSet<T> treeSet = TreeSet.ofAll(tree.comparator(), iterator().takeWhile(predicate));
         return (treeSet.length() == length()) ? this : treeSet;
     }
@@ -949,7 +908,6 @@ public TreeSet<T> takeWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super TreeSet<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -961,7 +919,6 @@ public java.util.TreeSet<T> toJavaSet() {
     @SuppressWarnings("unchecked")
     @Override
     public TreeSet<T> union(Set<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if (elements instanceof TreeSet) {
             final TreeSet<T> that = (TreeSet<T>) elements;
             return that.isEmpty() ? this : new TreeSet<>(tree.union(that.tree));
@@ -972,21 +929,17 @@ public TreeSet<T> union(Set<? extends T> elements) {
 
     @Override
     public <U> TreeSet<Tuple2<T, U>> zip(Iterable<? extends U> that) {
-        Objects.requireNonNull(that, "that is null");
         final Comparator<Tuple2<T, U>> tuple2Comparator = Tuple2.comparator(tree.comparator(), Comparators.naturalComparator());
         return TreeSet.ofAll(tuple2Comparator, iterator().zipWith(that, Tuple::of));
     }
 
     @Override
     public <U, R> TreeSet<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return TreeSet.ofAll(Comparators.naturalComparator(), iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> TreeSet<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         final Comparator<Tuple2<T, U>> tuple2Comparator = Tuple2.comparator(tree.comparator(), Comparators.naturalComparator());
         return TreeSet.ofAll(tuple2Comparator, iterator().zipAll(that, thisElem, thatElem));
     }
diff --git a/src/main/java/io/vavr/collection/Vector.java b/src/main/java/io/vavr/collection/Vector.java
index 1a26e08d9..e435cb2e4 100644
--- a/src/main/java/io/vavr/collection/Vector.java
+++ b/src/main/java/io/vavr/collection/Vector.java
@@ -124,7 +124,6 @@ public static <T> Vector<T> of(T element) {
     @SafeVarargs
     @SuppressWarnings("varargs")
     public static <T> Vector<T> of(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -139,7 +138,6 @@ public static <T> Vector<T> of(T... elements) {
      * @throws NullPointerException if {@code f} is null
      */
     public static <T> Vector<T> tabulate(int n, Function<? super Integer, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return io.vavr.collection.Collections.tabulate(n, f, empty(), Vector::of);
     }
 
@@ -153,7 +151,6 @@ public static <T> Vector<T> tabulate(int n, Function<? super Integer, ? extends
      * @throws NullPointerException if {@code s} is null
      */
     public static <T> Vector<T> fill(int n, Supplier<? extends T> s) {
-        Objects.requireNonNull(s, "s is null");
         return io.vavr.collection.Collections.fill(n, s, empty(), Vector::of);
     }
 
@@ -182,7 +179,6 @@ public static <T> Vector<T> fill(int n, T element) {
      */
     @SuppressWarnings("unchecked")
     public static <T> Vector<T> ofAll(Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable, "iterable is null");
         if (iterable instanceof Traversable && io.vavr.collection.Collections.isEmpty(iterable)) {
             return empty();
         }
@@ -205,7 +201,6 @@ public static <T> Vector<T> ofAll(Iterable<? extends T> iterable) {
      * @return A Vector containing the given elements in the same order.
      */
     public static <T> Vector<T> ofAll(java.util.stream.Stream<? extends T> javaStream) {
-        Objects.requireNonNull(javaStream, "javaStream is null");
         return ofAll(Iterator.ofAll(javaStream.iterator()));
     }
 
@@ -217,7 +212,6 @@ public static <T> Vector<T> ofAll(java.util.stream.Stream<? extends T> javaStrea
      * @throws NullPointerException if elements is null
      */
     public static Vector<Boolean> ofAll(boolean... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -229,7 +223,6 @@ public static Vector<Boolean> ofAll(boolean... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Byte> ofAll(byte... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -241,7 +234,6 @@ public static Vector<Byte> ofAll(byte... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Character> ofAll(char... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -253,7 +245,6 @@ public static Vector<Character> ofAll(char... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Double> ofAll(double... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -265,7 +256,6 @@ public static Vector<Double> ofAll(double... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Float> ofAll(float... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -277,7 +267,6 @@ public static Vector<Float> ofAll(float... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Integer> ofAll(int... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -289,7 +278,6 @@ public static Vector<Integer> ofAll(int... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Long> ofAll(long... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -301,7 +289,6 @@ public static Vector<Long> ofAll(long... elements) {
      * @throws NullPointerException if elements is null
      */
     public static Vector<Short> ofAll(short... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         return ofAll(BitMappedTrie.ofAll(elements));
     }
 
@@ -620,7 +607,6 @@ public static <T> Vector<T> unfold(T seed, Function<? super T, Option<Tuple2<? e
 
     @Override
     public Vector<T> appendAll(Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable, "iterable is null");
         if (isEmpty()) {
             return ofAll(iterable);
         }
@@ -669,14 +655,12 @@ public <R> Vector<R> collect(PartialFunction<? super T, ? extends R> partialFunc
 
     @Override
     public Vector<T> distinctBy(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         final java.util.Set<T> seen = new java.util.TreeSet<>(comparator);
         return filter(seen::add);
     }
 
     @Override
     public <U> Vector<T> distinctBy(Function<? super T, ? extends U> keyExtractor) {
-        Objects.requireNonNull(keyExtractor, "keyExtractor is null");
         final java.util.Set<U> seen = new java.util.HashSet<>(length());
         return filter(t -> seen.add(keyExtractor.apply(t)));
     }
@@ -693,7 +677,6 @@ public Vector<T> dropUntil(Predicate<? super T> predicate) {
 
     @Override
     public Vector<T> dropWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropUntil(predicate.negate());
     }
 
@@ -709,25 +692,21 @@ public Vector<T> dropRightUntil(Predicate<? super T> predicate) {
 
     @Override
     public Vector<T> dropRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return dropRightUntil(predicate.negate());
     }
 
     @Override
     public Vector<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return wrap(trie.filter(predicate));
     }
 
     @Override
     public Vector<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Collections.filterNot(this, predicate);
     }
 
     @Override
     public <U> Vector<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         final Iterator<? extends U> results = iterator().flatMap(mapper);
         return ofAll(results);
     }
@@ -787,7 +766,6 @@ public Vector<T> init() {
 
     @Override
     public Vector<T> insertAll(int index, Iterable<? extends T> elements) {
-        Objects.requireNonNull(elements, "elements is null");
         if ((index >= 0) && (index <= length())) {
             final Vector<T> begin = take(index).appendAll(elements);
             final Vector<T> end = drop(index);
@@ -849,7 +827,6 @@ public int lastIndexOf(T element, int end) {
 
     @Override
     public <U> Vector<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(trie.map(mapper));
     }
 
@@ -895,7 +872,6 @@ public Vector<T> patch(int from, Iterable<? extends T> that, int replaced) {
 
     @Override
     public Tuple2<Vector<T>, Vector<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final ArrayList<T> left = new ArrayList<>(), right = new ArrayList<>();
         for (int i = 0; i < length(); i++) {
             final T t = get(i);
@@ -906,7 +882,6 @@ public Tuple2<Vector<T>, Vector<T>> partition(Predicate<? super T> predicate) {
 
     @Override
     public Vector<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (!isEmpty()) {
             action.accept(head());
         }
@@ -935,7 +910,6 @@ public Vector<Vector<T>> permutations() {
 
     @Override
     public Vector<T> prependAll(Iterable<? extends T> iterable) {
-        Objects.requireNonNull(iterable, "iterable is null");
         if (isEmpty()) {
             return ofAll(iterable);
         }
@@ -957,7 +931,6 @@ public Vector<T> remove(T element) {
 
     @Override
     public Vector<T> removeFirst(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = 0; i < length(); i++) {
             if (predicate.test(get(i))) {
                 return removeAt(i);
@@ -968,7 +941,6 @@ public Vector<T> removeFirst(Predicate<T> predicate) {
 
     @Override
     public Vector<T> removeLast(Predicate<T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = length() - 1; i >= 0; i--) {
             if (predicate.test(get(i))) {
                 return removeAt(i);
@@ -1105,7 +1077,6 @@ public Vector<T> sorted() {
 
     @Override
     public Vector<T> sorted(Comparator<? super T> comparator) {
-        Objects.requireNonNull(comparator, "comparator is null");
         return isEmpty() ? this : toJavaStream().sorted(comparator).collect(collector());
     }
 
@@ -1121,7 +1092,6 @@ public <U> Vector<T> sortBy(Comparator<? super U> comparator, Function<? super T
 
     @Override
     public Tuple2<Vector<T>, Vector<T>> span(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return Tuple.of(takeWhile(predicate), dropWhile(predicate));
     }
 
@@ -1132,14 +1102,12 @@ public Tuple2<Vector<T>, Vector<T>> splitAt(int n) {
 
     @Override
     public Tuple2<Vector<T>, Vector<T>> splitAt(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         final Vector<T> init = takeWhile(predicate.negate());
         return Tuple.of(init, drop(init.size()));
     }
 
     @Override
     public Tuple2<Vector<T>, Vector<T>> splitAtInclusive(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         for (int i = 0; i < length(); i++) {
             final T value = get(i);
             if (predicate.test(value)) {
@@ -1189,7 +1157,6 @@ public Vector<T> takeUntil(Predicate<? super T> predicate) {
 
     @Override
     public Vector<T> takeWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeUntil(predicate.negate());
     }
 
@@ -1205,7 +1172,6 @@ public Vector<T> takeRightUntil(Predicate<? super T> predicate) {
 
     @Override
     public Vector<T> takeRightWhile(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return takeRightUntil(predicate.negate());
     }
 
@@ -1218,7 +1184,6 @@ public Vector<T> takeRightWhile(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code f} is null
      */
     public <U> U transform(Function<? super Vector<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1233,7 +1198,6 @@ public Vector<T> update(int index, T element) {
 
     @Override
     public Vector<T> update(int index, Function<? super T, ? extends T> updater) {
-        Objects.requireNonNull(updater, "updater is null");
         return update(index, updater.apply(get(index)));
     }
 
@@ -1244,14 +1208,11 @@ public <U> Vector<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> Vector<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> Vector<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -1262,7 +1223,6 @@ public Vector<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> Vector<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return ofAll(iterator().zipWithIndex(mapper));
     }
 
diff --git a/src/main/java/io/vavr/concurrent/Future.java b/src/main/java/io/vavr/concurrent/Future.java
index 00b7e91ce..746eacafc 100644
--- a/src/main/java/io/vavr/concurrent/Future.java
+++ b/src/main/java/io/vavr/concurrent/Future.java
@@ -125,7 +125,6 @@ public interface Future<T> extends Iterable<T>, Value<T> {
      * @throws NullPointerException if exception is null
      */
     static <T> Future<T> failed(Throwable exception) {
-        Objects.requireNonNull(exception, "exception is null");
         return failed(DEFAULT_EXECUTOR, exception);
     }
 
@@ -139,8 +138,6 @@ static <T> Future<T> failed(Throwable exception) {
      * @throws NullPointerException if executor or exception is null
      */
     static <T> Future<T> failed(Executor executor, Throwable exception) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(exception, "exception is null");
         return FutureImpl.of(executor, Try.failure(exception));
     }
 
@@ -174,9 +171,6 @@ static <T> Future<Option<T>> find(Iterable<? extends Future<? extends T>> future
      * @throws NullPointerException if one of the arguments is null
      */
     static <T> Future<Option<T>> find(Executor executor, Iterable<? extends Future<? extends T>> futures, Predicate<? super T> predicate) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(futures, "futures is null");
-        Objects.requireNonNull(predicate, "predicate is null");
         final List<Future<? extends T>> list = List.ofAll(futures);
         if (list.isEmpty()) {
             return successful(executor, Option.none());
@@ -229,8 +223,6 @@ static <T> Future<T> firstCompletedOf(Iterable<? extends Future<? extends T>> fu
      * @throws NullPointerException if executor or futures is null
      */
     static <T> Future<T> firstCompletedOf(Executor executor, Iterable<? extends Future<? extends T>> futures) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(futures, "futures is null");
         return run(executor, complete -> futures.forEach(future -> future.onComplete(complete::with)));
     }
 
@@ -268,9 +260,6 @@ static <T, U> Future<U> fold(Iterable<? extends Future<? extends T>> futures, U
      * @throws NullPointerException if executor, futures or f is null.
      */
     static <T, U> Future<U> fold(Executor executor, Iterable<? extends Future<? extends T>> futures, U zero, BiFunction<? super U, ? super T, ? extends U> f) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(futures, "futures is null");
-        Objects.requireNonNull(f, "f is null");
         if (!futures.iterator().hasNext()) {
             return successful(executor, zero);
         } else {
@@ -287,7 +276,6 @@ static <T, U> Future<U> fold(Executor executor, Iterable<? extends Future<? exte
      * @throws NullPointerException if future is null
      */
     static <T> Future<T> fromJavaFuture(java.util.concurrent.Future<T> future) {
-        Objects.requireNonNull(future, "future is null");
         return of(DEFAULT_EXECUTOR, future::get);
     }
 
@@ -301,8 +289,6 @@ static <T> Future<T> fromJavaFuture(java.util.concurrent.Future<T> future) {
      * @throws NullPointerException if executor or future is null
      */
     static <T> Future<T> fromJavaFuture(Executor executor, java.util.concurrent.Future<T> future) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(future, "future is null");
         return of(executor, future::get);
     }
 
@@ -328,8 +314,6 @@ static <T> Future<T> fromCompletableFuture(CompletableFuture<T> future) {
      * @throws NullPointerException if executor or future is null
      */
     static <T> Future<T> fromCompletableFuture(Executor executor, CompletableFuture<T> future) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(future, "future is null");
         if (future.isDone() || future.isCompletedExceptionally() || future.isCancelled()) {
             return fromTry(Try.of(future::get).recoverWith(error -> Try.failure(error.getCause())));
         } else {
@@ -361,8 +345,6 @@ static <T> Future<T> fromTry(Try<? extends T> result) {
      * @throws NullPointerException if executor or result is null
      */
     static <T> Future<T> fromTry(Executor executor, Try<? extends T> result) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(result, "result is null");
         return FutureImpl.of(executor, result);
     }
 
@@ -391,7 +373,6 @@ static <T> Future<T> narrow(Future<? extends T> future) {
      */
     @Deprecated
     static <T> Future<T> ofSupplier(Supplier<? extends T> computation) {
-        Objects.requireNonNull(computation, "computation is null");
         return of(DEFAULT_EXECUTOR, computation::get);
     }
 
@@ -407,8 +388,6 @@ static <T> Future<T> ofSupplier(Supplier<? extends T> computation) {
      */
     @Deprecated
     static <T> Future<T> ofSupplier(Executor executor, Supplier<? extends T> computation) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(computation, "computation is null");
         return of(executor, computation::get);
     }
 
@@ -423,7 +402,6 @@ static <T> Future<T> ofSupplier(Executor executor, Supplier<? extends T> computa
      */
     @Deprecated
     static <T> Future<T> ofCallable(Callable<? extends T> computation) {
-        Objects.requireNonNull(computation, "computation is null");
         return of(DEFAULT_EXECUTOR, computation::call);
     }
 
@@ -439,8 +417,6 @@ static <T> Future<T> ofCallable(Callable<? extends T> computation) {
      */
     @Deprecated
     static <T> Future<T> ofCallable(Executor executor, Callable<? extends T> computation) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(computation, "computation is null");
         return of(executor, computation::call);
     }
 
@@ -454,7 +430,6 @@ static <T> Future<T> ofCallable(Executor executor, Callable<? extends T> computa
      */
     @Deprecated
     static Future<Void> runRunnable(Runnable computation) {
-        Objects.requireNonNull(computation, "computation is null");
         return run(DEFAULT_EXECUTOR, computation::run);
     }
 
@@ -469,8 +444,6 @@ static Future<Void> runRunnable(Runnable computation) {
      */
     @Deprecated
     static Future<Void> runRunnable(Executor executor, Runnable computation) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(computation, "computation is null");
         return run(executor, computation::run);
     }
 
@@ -496,8 +469,6 @@ static <T> Future<T> of(CheckedFunction0<? extends T> computation) {
      * @throws NullPointerException if one of executor or computation is null.
      */
     static <T> Future<T> of(Executor executor, CheckedFunction0<? extends T> computation) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(computation, "computation is null");
         return FutureImpl.async(executor, complete -> complete.with(Try.of(computation)));
     }
 
@@ -610,9 +581,6 @@ static <T> Future<T> reduce(Iterable<? extends Future<? extends T>> futures, BiF
      * @throws NullPointerException if executor, futures or f is null.
      */
     static <T> Future<T> reduce(Executor executor, Iterable<? extends Future<? extends T>> futures, BiFunction<? super T, ? super T, ? extends T> f) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(futures, "futures is null");
-        Objects.requireNonNull(f, "f is null");
         if (!futures.iterator().hasNext()) {
             throw new NoSuchElementException("Future.reduce on empty futures");
         } else {
@@ -640,8 +608,6 @@ static Future<Void> run(CheckedRunnable unit) {
      * @throws NullPointerException if one of executor or unit is null.
      */
     static Future<Void> run(Executor executor, CheckedRunnable unit) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(unit, "unit is null");
         return of(executor, () -> {
             unit.run();
             return null;
@@ -699,8 +665,6 @@ static <T> Future<Seq<T>> sequence(Iterable<? extends Future<? extends T>> futur
      * @throws NullPointerException if executor or futures is null.
      */
     static <T> Future<Seq<T>> sequence(Executor executor, Iterable<? extends Future<? extends T>> futures) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(futures, "futures is null");
         final Future<Seq<T>> zero = successful(executor, Stream.empty());
         final BiFunction<Future<Seq<T>>, Future<? extends T>, Future<Seq<T>>> f =
                 (result, future) -> result.flatMap(seq -> future.map(seq::append));
@@ -728,7 +692,6 @@ static <T> Future<T> successful(T result) {
      * @throws NullPointerException if executor is null
      */
     static <T> Future<T> successful(Executor executor, T result) {
-        Objects.requireNonNull(executor, "executor is null");
         return FutureImpl.of(executor, Try.success(result));
     }
 
@@ -772,9 +735,6 @@ static <T, U> Future<Seq<U>> traverse(Iterable<? extends T> values, Function<? s
      * @throws NullPointerException if executor, values or f is null.
      */
     static <T, U> Future<Seq<U>> traverse(Executor executor, Iterable<? extends T> values, Function<? super T, ? extends Future<? extends U>> mapper) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequence(executor, Iterator.ofAll(values).map(mapper));
     }
 
@@ -799,7 +759,6 @@ static <T, U> Future<Seq<U>> traverse(Executor executor, Iterable<? extends T> v
      * @throws NullPointerException if action is null
      */
     default Future<T> andThen(Consumer<? super Try<T>> action) {
-        Objects.requireNonNull(action, "action is null");
         return run(executor(), complete ->
                 onComplete(t -> {
                     Try.run(() -> action.accept(t));
@@ -880,7 +839,8 @@ default boolean cancel() {
      * @throws NullPointerException if {@code partialFunction} is null
      */
     default <R> Future<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
+        // #2711: CRITICAL: without this null check the future might never complete.
+        Objects.requireNonNull(partialFunction, "partialFunction");
         return run(executor(), complete ->
             onComplete(result -> complete.with(result.collect(partialFunction)))
         );
@@ -949,7 +909,6 @@ default Future<Throwable> failed() {
      * @throws NullPointerException if that is null
      */
     default Future<T> fallbackTo(Future<? extends T> that) {
-        Objects.requireNonNull(that, "that is null");
         return run(executor(), complete ->
             onComplete(t -> {
                 if (t.isSuccess()) {
@@ -969,7 +928,6 @@ default Future<T> fallbackTo(Future<? extends T> that) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default Future<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterTry(predicate::test);
     }
 
@@ -981,7 +939,6 @@ default Future<T> filter(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     default Future<T> filterTry(CheckedPredicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return run(executor(), complete -> onComplete(result -> complete.with(result.filterTry(predicate))));
     }
 
@@ -1052,7 +1009,6 @@ default boolean isFailure() {
      * @throws NullPointerException if {@code action} is null.
      */
     default Future<T> onFailure(Consumer<? super Throwable> action) {
-        Objects.requireNonNull(action, "action is null");
         return onComplete(result -> result.onFailure(action));
     }
 
@@ -1064,7 +1020,6 @@ default Future<T> onFailure(Consumer<? super Throwable> action) {
      * @throws NullPointerException if {@code action} is null.
      */
     default Future<T> onSuccess(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         return onComplete(result -> result.onSuccess(action));
     }
 
@@ -1082,7 +1037,6 @@ default Future<T> onSuccess(Consumer<? super T> action) {
      * @throws NullPointerException if {@code f} is null
      */
     default Future<T> recover(Function<? super Throwable, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         return transformValue(t -> t.recover(f));
     }
 
@@ -1105,8 +1059,6 @@ default Future<T> recover(Function<? super Throwable, ? extends T> f) {
      * @throws NullPointerException if {@code f} is null
      */
     default <X extends Throwable> Future<T> recover(Class<X> exceptionType, Function<? super X, ? extends T> f) {
-        Objects.requireNonNull(exceptionType, "exceptionType is null");
-        Objects.requireNonNull(f, "f is null");
         return transformValue(t -> t.recover(exceptionType, f));
     }
 
@@ -1124,7 +1076,6 @@ default <X extends Throwable> Future<T> recover(Class<X> exceptionType, Function
      * @throws NullPointerException if {@code f} is null
      */
     default Future<T> recoverWith(Function<? super Throwable, ? extends Future<? extends T>> f) {
-        Objects.requireNonNull(f, "f is null");
         return run(executor(), complete ->
             onComplete(t -> {
                 if (t.isFailure()) {
@@ -1146,7 +1097,6 @@ default Future<T> recoverWith(Function<? super Throwable, ? extends Future<? ext
      * @throws NullPointerException if {@code f} is null
      */
     default <U> U transform(Function<? super Future<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1159,7 +1109,6 @@ default <U> U transform(Function<? super Future<T>, ? extends U> f) {
      * @throws NullPointerException if {@code f} is null
      */
     default <U> Future<U> transformValue(Function<? super Try<T>, ? extends Try<? extends U>> f) {
-        Objects.requireNonNull(f, "f is null");
         return run(executor(), complete ->
             onComplete(t -> Try.run(() -> complete.with(f.apply(t)))
                     .onFailure(x -> complete.with(Try.failure(x)))
@@ -1179,7 +1128,6 @@ default <U> Future<U> transformValue(Function<? super Try<T>, ? extends Try<? ex
      * @throws NullPointerException if {@code that} is null
      */
     default <U> Future<Tuple2<T, U>> zip(Future<? extends U> that) {
-        Objects.requireNonNull(that, "that is null");
         return zipWith(that, Tuple::of);
     }
 
@@ -1198,8 +1146,6 @@ default <U> Future<Tuple2<T, U>> zip(Future<? extends U> that) {
      */
     @SuppressWarnings({"deprecation", "unchecked"})
     default <U, R> Future<R> zipWith(Future<? extends U> that, BiFunction<? super T, ? super U, ? extends R> combinator) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(combinator, "combinator is null");
         return run(executor(), complete ->
             onComplete(res1 -> {
                 if (res1.isFailure()) {
@@ -1217,12 +1163,10 @@ default <U, R> Future<R> zipWith(Future<? extends U> that, BiFunction<? super T,
     // -- Value & Monad implementation
 
     default <U> Future<U> flatMap(Function<? super T, ? extends Future<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return flatMapTry(mapper::apply);
     }
 
     default <U> Future<U> flatMapTry(CheckedFunction1<? super T, ? extends Future<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return run(executor(), complete ->
             onComplete(result -> result.mapTry(mapper)
                     .onSuccess(future -> future.onComplete(complete::with))
@@ -1239,7 +1183,6 @@ default <U> Future<U> flatMapTry(CheckedFunction1<? super T, ? extends Future<?
      */
     @Override
     default void forEach(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         onComplete(result -> result.forEach(action));
     }
 
@@ -1303,17 +1246,14 @@ default Iterator<T> iterator() {
 
     @Override
     default <U> Future<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return transformValue(t -> t.map(mapper));
     }
 
     default <U> Future<U> mapTry(CheckedFunction1<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return transformValue(t -> t.mapTry(mapper));
     }
 
     default Future<T> orElse(Future<? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         return run(executor(), complete ->
             onComplete(result -> {
                 if (result.isSuccess()) {
@@ -1326,7 +1266,6 @@ default Future<T> orElse(Future<? extends T> other) {
     }
 
     default Future<T> orElse(Supplier<? extends Future<? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return run(executor(), complete ->
             onComplete(result -> {
                 if (result.isSuccess()) {
@@ -1340,7 +1279,6 @@ default Future<T> orElse(Supplier<? extends Future<? extends T>> supplier) {
 
     @Override
     default Future<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         onSuccess(action);
         return this;
     }
diff --git a/src/main/java/io/vavr/concurrent/FutureImpl.java b/src/main/java/io/vavr/concurrent/FutureImpl.java
index ba7c62aad..697872c72 100644
--- a/src/main/java/io/vavr/concurrent/FutureImpl.java
+++ b/src/main/java/io/vavr/concurrent/FutureImpl.java
@@ -93,7 +93,8 @@ final class FutureImpl<T> implements Future<T> {
 
     // single constructor
     private FutureImpl(Executor executor, Option<Try<T>> value, Queue<Consumer<Try<T>>> actions, Queue<Thread> waiters, Computation<T> computation) {
-        this.executor = executor;
+        // #2711: null check necessary
+        this.executor = Objects.requireNonNull(executor, "executor");
         synchronized (lock) {
             this.cancelled = false;
             this.value = value;
@@ -179,7 +180,6 @@ public Future<T> await() {
     @Override
     public Future<T> await(long timeout, TimeUnit unit) {
         final long now = System.nanoTime();
-        Objects.requireNonNull(unit, "unit is null");
         if (timeout < 0) {
             throw new IllegalArgumentException("negative timeout");
         }
@@ -324,7 +324,6 @@ public boolean isCompleted() {
     @SuppressWarnings("unchecked")
     @Override
     public Future<T> onComplete(Consumer<? super Try<T>> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isCompleted()) {
             perform(action);
         } else {
@@ -361,7 +360,6 @@ public String toString() {
      * @throws NullPointerException  if the given {@code value} is null.
      */
     boolean tryComplete(Try<? extends T> value) {
-        Objects.requireNonNull(value, "value is null");
         if (isCompleted()) {
             return false;
         } else {
diff --git a/src/main/java/io/vavr/concurrent/Promise.java b/src/main/java/io/vavr/concurrent/Promise.java
index 594d5eb5f..1c0e59ef6 100644
--- a/src/main/java/io/vavr/concurrent/Promise.java
+++ b/src/main/java/io/vavr/concurrent/Promise.java
@@ -93,7 +93,6 @@ public interface Promise<T> {
      * @throws NullPointerException if exception is null
      */
     static <T> Promise<T> failed(Throwable exception) {
-        Objects.requireNonNull(exception, "exception is null");
         return failed(DEFAULT_EXECUTOR, exception);
     }
 
@@ -107,8 +106,6 @@ static <T> Promise<T> failed(Throwable exception) {
      * @throws NullPointerException if executor or exception is null
      */
     static <T> Promise<T> failed(Executor executor, Throwable exception) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(exception, "exception is null");
         return Promise.<T> make(executor).failure(exception);
     }
 
@@ -134,8 +131,6 @@ static <T> Promise<T> fromTry(Try<? extends T> result) {
      * @throws NullPointerException if executor or result is null
      */
     static <T> Promise<T> fromTry(Executor executor, Try<? extends T> result) {
-        Objects.requireNonNull(executor, "executor is null");
-        Objects.requireNonNull(result, "result is null");
         return Promise.<T> make(executor).complete(result);
     }
 
@@ -159,7 +154,6 @@ static <T> Promise<T> make() {
      * @throws NullPointerException if executor is null
      */
     static <T> Promise<T> make(Executor executor) {
-        Objects.requireNonNull(executor, "executor is null");
         return new PromiseImpl<>(FutureImpl.of(executor));
     }
 
@@ -198,7 +192,6 @@ static <T> Promise<T> successful(T result) {
      * @throws NullPointerException if executor is null
      */
     static <T> Promise<T> successful(Executor executor, T result) {
-        Objects.requireNonNull(executor, "executor is null");
         return Promise.<T> make(executor).success(result);
     }
 
diff --git a/src/main/java/io/vavr/control/Either.java b/src/main/java/io/vavr/control/Either.java
index 61f00a2b1..938fa4b85 100644
--- a/src/main/java/io/vavr/control/Either.java
+++ b/src/main/java/io/vavr/control/Either.java
@@ -218,8 +218,6 @@ public final RightProjection<L, R> right() {
      * @return A new Either instance
      */
     public final <X, Y> Either<X, Y> bimap(Function<? super L, ? extends X> leftMapper, Function<? super R, ? extends Y> rightMapper) {
-        Objects.requireNonNull(leftMapper, "leftMapper is null");
-        Objects.requireNonNull(rightMapper, "rightMapper is null");
         if (isRight()) {
             return new Right<>(rightMapper.apply(get()));
         } else {
@@ -248,8 +246,6 @@ public final <X, Y> Either<X, Y> bimap(Function<? super L, ? extends X> leftMapp
      * @return A value of type U
      */
     public final <U> U fold(Function<? super L, ? extends U> leftMapper, Function<? super R, ? extends U> rightMapper) {
-        Objects.requireNonNull(leftMapper, "leftMapper is null");
-        Objects.requireNonNull(rightMapper, "rightMapper is null");
         if (isRight()) {
             return rightMapper.apply(get());
         } else {
@@ -286,7 +282,6 @@ public final <U> U fold(Function<? super L, ? extends U> leftMapper, Function<?
      */
     @SuppressWarnings("unchecked")
     public static <L,R> Either<Seq<L>, Seq<R>> sequence(Iterable<? extends Either<? extends L, ? extends R>> eithers) {
-        Objects.requireNonNull(eithers, "eithers is null");
         return Iterator.ofAll((Iterable<Either<L, R>>) eithers)
                 .partition(Either::isLeft)
                 .apply((leftPartition, rightPartition) -> leftPartition.hasNext()
@@ -320,8 +315,6 @@ public static <L,R> Either<Seq<L>, Seq<R>> sequence(Iterable<? extends Either<?
      * @throws NullPointerException if values or f is null.
      */
     public static <L, R, T> Either<Seq<L>, Seq<R>> traverse(Iterable<? extends T> values, Function<? super T, ? extends Either<? extends L, ? extends R>> mapper) {
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequence(Iterator.ofAll(values).map(mapper));
     }
 
@@ -353,7 +346,6 @@ public static <L, R, T> Either<Seq<L>, Seq<R>> traverse(Iterable<? extends T> va
      * @throws NullPointerException if {@code eithers} is null
      */
     public static <L,R> Either<L, Seq<R>> sequenceRight(Iterable<? extends Either<? extends L, ? extends R>> eithers) {
-        Objects.requireNonNull(eithers, "eithers is null");
         Vector<R> rightValues = Vector.empty();
         for (Either<? extends L, ? extends R> either : eithers) {
             if (either.isRight()) {
@@ -387,8 +379,6 @@ public static <L,R> Either<L, Seq<R>> sequenceRight(Iterable<? extends Either<?
      * @throws NullPointerException if values or f is null.
      */
     public static <L, R, T> Either<L, Seq<R>> traverseRight(Iterable<? extends T> values, Function<? super T, ? extends Either<? extends L, ? extends R>> mapper) {
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequenceRight(Iterator.ofAll(values).map(mapper));
     }
 
@@ -406,7 +396,6 @@ public static <L, R, T> Either<L, Seq<R>> traverseRight(Iterable<? extends T> va
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Either<L, R>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -426,7 +415,6 @@ public final <U> U transform(Function<? super Either<L, R>, ? extends U> f) {
      * {@code other} by applying the Left value.
      */
     public final R getOrElseGet(Function<? super L, ? extends R> other) {
-        Objects.requireNonNull(other, "other is null");
         if (isRight()) {
             return get();
         } else {
@@ -445,7 +433,6 @@ public final R getOrElseGet(Function<? super L, ? extends R> other) {
      * @param action an action which consumes a Left value
      */
     public final void orElseRun(Consumer<? super L> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isLeft()) {
             action.accept(getLeft());
         }
@@ -470,7 +457,6 @@ public final void orElseRun(Consumer<? super L> action) {
      * @throws X if the projected Either is a Left
      */
     public final <X extends Throwable> R getOrElseThrow(Function<? super L, X> exceptionFunction) throws X {
-        Objects.requireNonNull(exceptionFunction, "exceptionFunction is null");
         if (isRight()) {
             return get();
         } else {
@@ -518,7 +504,6 @@ public final Either<R, L> swap() {
      */
     @SuppressWarnings("unchecked")
     public final Either<L, R> recoverWith(Function<? super L, ? extends Either<? extends L, ? extends R>> recoveryFunction) {
-        Objects.requireNonNull(recoveryFunction, "recoveryFunction is null");
         if (isLeft()) {
             return (Either<L, R>) recoveryFunction.apply(getLeft());
         } else {
@@ -544,7 +529,6 @@ public final Either<L, R> recoverWith(Function<? super L, ? extends Either<? ext
      * @throws NullPointerException if the given {@code recoveryFunction} is null
      */
     public final Either<L, R> recover(Function<? super L, ? extends R> recoveryFunction) {
-        Objects.requireNonNull(recoveryFunction, "recoveryFunction is null");
         if (isLeft()) {
             return Either.right(recoveryFunction.apply(getLeft()));
         } else {
@@ -572,7 +556,6 @@ public final Either<L, R> recover(Function<? super L, ? extends R> recoveryFunct
      */
     @SuppressWarnings("unchecked")
     public final <U> Either<L, U> flatMap(Function<? super R, ? extends Either<L, ? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isRight()) {
             return (Either<L, U>) mapper.apply(get());
         } else {
@@ -599,7 +582,6 @@ public final <U> Either<L, U> flatMap(Function<? super R, ? extends Either<L, ?
     @SuppressWarnings("unchecked")
     @Override
     public final <U> Either<L, U> map(Function<? super R, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isRight()) {
             return Either.right(mapper.apply(get()));
         } else {
@@ -625,7 +607,6 @@ public final <U> Either<L, U> map(Function<? super R, ? extends U> mapper) {
      */
     @SuppressWarnings("unchecked")
     public final <U> Either<U, R> mapLeft(Function<? super L, ? extends U> leftMapper) {
-        Objects.requireNonNull(leftMapper, "leftMapper is null");
         if (isLeft()) {
             return Either.left(leftMapper.apply(getLeft()));
         } else {
@@ -644,7 +625,6 @@ public final <U> Either<U, R> mapLeft(Function<? super L, ? extends U> leftMappe
      * @throws NullPointerException if {@code predicate} is null
      */
     public final Option<Either<L, R>> filter(Predicate<? super R> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return isLeft() || predicate.test(get()) ? Option.some(this) : Option.none();
     }
 
@@ -657,7 +637,6 @@ public final Option<Either<L, R>> filter(Predicate<? super R> predicate) {
      *
      */
     public final Option<Either<L, R>> filterNot(Predicate<? super R> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
@@ -681,8 +660,6 @@ public final Option<Either<L, R>> filterNot(Predicate<? super R> predicate) {
      * @throws NullPointerException if {@code predicate} is null
      */
     public final Either<L,R> filterOrElse(Predicate<? super R> predicate, Function<? super R, ? extends L> zero) {
-        Objects.requireNonNull(predicate, "predicate is null");
-        Objects.requireNonNull(zero, "zero is null");
         if (isLeft() || predicate.test(get())) {
             return this;
         } else {
@@ -706,13 +683,11 @@ public final boolean isEmpty() {
 
     @SuppressWarnings("unchecked")
     public final Either<L, R> orElse(Either<? extends L, ? extends R> other) {
-        Objects.requireNonNull(other, "other is null");
         return isRight() ? this : (Either<L, R>) other;
     }
 
     @SuppressWarnings("unchecked")
     public final Either<L, R> orElse(Supplier<? extends Either<? extends L, ? extends R>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isRight() ? this : (Either<L, R>) supplier.get();
     }
 
@@ -764,8 +739,6 @@ public final Iterator<R> iterator() {
      * @return this instance
      */
     public final Either<L, R> peek(Consumer<? super L> leftAction, Consumer<? super R> rightAction) {
-        Objects.requireNonNull(leftAction, "leftAction is null");
-        Objects.requireNonNull(rightAction, "rightAction is null");
 
         if (isLeft()) {
             leftAction.accept(getLeft());
@@ -778,7 +751,6 @@ public final Either<L, R> peek(Consumer<? super L> leftAction, Consumer<? super
 
     @Override
     public final Either<L, R> peek(Consumer<? super R> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isRight()) {
             action.accept(get());
         }
@@ -786,7 +758,6 @@ public final Either<L, R> peek(Consumer<? super R> action) {
     }
 
     public final Either<L, R> peekLeft(Consumer<? super L> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isLeft()) {
             action.accept(getLeft());
         }
@@ -892,13 +863,11 @@ public L get() {
 
         @SuppressWarnings("unchecked")
         public LeftProjection<L, R> orElse(LeftProjection<? extends L, ? extends R> other) {
-            Objects.requireNonNull(other, "other is null");
             return either.isLeft() ? this : (LeftProjection<L, R>) other;
         }
 
         @SuppressWarnings("unchecked")
         public LeftProjection<L, R> orElse(Supplier<? extends LeftProjection<? extends L, ? extends R>> supplier) {
-            Objects.requireNonNull(supplier, "supplier is null");
             return either.isLeft() ? this : (LeftProjection<L, R>) supplier.get();
         }
 
@@ -922,7 +891,6 @@ public L getOrElse(L other) {
          * {@code other} by applying the Right value.
          */
         public L getOrElseGet(Function<? super R, ? extends L> other) {
-            Objects.requireNonNull(other, "other is null");
             if (either.isLeft()) {
                 return either.getLeft();
             } else {
@@ -936,7 +904,6 @@ public L getOrElseGet(Function<? super R, ? extends L> other) {
          * @param action an action which consumes a Right value
          */
         public void orElseRun(Consumer<? super R> action) {
-            Objects.requireNonNull(action, "action is null");
             if (either.isRight()) {
                 action.accept(either.get());
             }
@@ -952,7 +919,6 @@ public void orElseRun(Consumer<? super R> action) {
          * @throws X if the projected Either is a Right
          */
         public <X extends Throwable> L getOrElseThrow(Function<? super R, X> exceptionFunction) throws X {
-            Objects.requireNonNull(exceptionFunction, "exceptionFunction is null");
             if (either.isLeft()) {
                 return either.getLeft();
             } else {
@@ -977,7 +943,6 @@ public Either<L, R> toEither() {
          * @return A new Option
          */
         public Option<LeftProjection<L, R>> filter(Predicate<? super L> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             return either.isRight() || predicate.test(either.getLeft()) ? Option.some(this) : Option.none();
         }
 
@@ -991,7 +956,6 @@ public Option<LeftProjection<L, R>> filter(Predicate<? super L> predicate) {
          */
         @SuppressWarnings("unchecked")
         public <U> LeftProjection<U, R> flatMap(Function<? super L, ? extends LeftProjection<? extends U, R>> mapper) {
-            Objects.requireNonNull(mapper, "mapper is null");
             if (either.isLeft()) {
                 return (LeftProjection<U, R>) mapper.apply(either.getLeft());
             } else {
@@ -1009,7 +973,6 @@ public <U> LeftProjection<U, R> flatMap(Function<? super L, ? extends LeftProjec
         @SuppressWarnings("unchecked")
         @Override
         public <U> LeftProjection<U, R> map(Function<? super L, ? extends U> mapper) {
-            Objects.requireNonNull(mapper, "mapper is null");
             if (either.isLeft()) {
                 return either.mapLeft((Function<L, U>) mapper).left();
             } else {
@@ -1025,7 +988,6 @@ public <U> LeftProjection<U, R> map(Function<? super L, ? extends U> mapper) {
          */
         @Override
         public LeftProjection<L, R> peek(Consumer<? super L> action) {
-            Objects.requireNonNull(action, "action is null");
             if (either.isLeft()) {
                 action.accept(either.getLeft());
             }
@@ -1041,7 +1003,6 @@ public LeftProjection<L, R> peek(Consumer<? super L> action) {
          * @throws NullPointerException if {@code f} is null
          */
         public <U> U transform(Function<? super LeftProjection<L, R>, ? extends U> f) {
-            Objects.requireNonNull(f, "f is null");
             return f.apply(this);
         }
 
@@ -1147,13 +1108,11 @@ public R get() {
 
         @SuppressWarnings("unchecked")
         public RightProjection<L, R> orElse(RightProjection<? extends L, ? extends R> other) {
-            Objects.requireNonNull(other, "other is null");
             return either.isRight() ? this : (RightProjection<L, R>) other;
         }
 
         @SuppressWarnings("unchecked")
         public RightProjection<L, R> orElse(Supplier<? extends RightProjection<? extends L, ? extends R>> supplier) {
-            Objects.requireNonNull(supplier, "supplier is null");
             return either.isRight() ? this : (RightProjection<L, R>) supplier.get();
         }
 
@@ -1184,7 +1143,6 @@ public R getOrElse(R other) {
          * {@code other} by applying the Left value.
          */
         public R getOrElseGet(Function<? super L, ? extends R> other) {
-            Objects.requireNonNull(other, "other is null");
             return either.getOrElseGet(other);
         }
 
@@ -1202,7 +1160,6 @@ public R getOrElseGet(Function<? super L, ? extends R> other) {
          * @param action an action which consumes a Left value
          */
         public void orElseRun(Consumer<? super L> action) {
-            Objects.requireNonNull(action, "action is null");
             either.orElseRun(action);
         }
 
@@ -1224,7 +1181,6 @@ public void orElseRun(Consumer<? super L> action) {
          * @throws X if the projected Either is a Left
          */
         public <X extends Throwable> R getOrElseThrow(Function<? super L, X> exceptionFunction) throws X {
-            Objects.requireNonNull(exceptionFunction, "exceptionFunction is null");
             return either.getOrElseThrow(exceptionFunction);
         }
 
@@ -1245,7 +1201,6 @@ public Either<L, R> toEither() {
          * @return A new Option
          */
         public Option<RightProjection<L, R>> filter(Predicate<? super R> predicate) {
-            Objects.requireNonNull(predicate, "predicate is null");
             return either.isLeft() || predicate.test(either.get()) ? Option.some(this) : Option.none();
         }
 
@@ -1259,7 +1214,6 @@ public Option<RightProjection<L, R>> filter(Predicate<? super R> predicate) {
          */
         @SuppressWarnings("unchecked")
         public <U> RightProjection<L, U> flatMap(Function<? super R, ? extends RightProjection<L, ? extends U>> mapper) {
-            Objects.requireNonNull(mapper, "mapper is null");
             if (either.isRight()) {
                 return (RightProjection<L, U>) mapper.apply(either.get());
             } else {
@@ -1277,7 +1231,6 @@ public <U> RightProjection<L, U> flatMap(Function<? super R, ? extends RightProj
         @SuppressWarnings("unchecked")
         @Override
         public <U> RightProjection<L, U> map(Function<? super R, ? extends U> mapper) {
-            Objects.requireNonNull(mapper, "mapper is null");
             if (either.isRight()) {
                 return either.map((Function<R, U>) mapper).right();
             } else {
@@ -1293,7 +1246,6 @@ public <U> RightProjection<L, U> map(Function<? super R, ? extends U> mapper) {
          */
         @Override
         public RightProjection<L, R> peek(Consumer<? super R> action) {
-            Objects.requireNonNull(action, "action is null");
             if (either.isRight()) {
                 action.accept(either.get());
             }
@@ -1309,7 +1261,6 @@ public RightProjection<L, R> peek(Consumer<? super R> action) {
          * @throws NullPointerException if {@code f} is null
          */
         public <U> U transform(Function<? super RightProjection<L, R>, ? extends U> f) {
-            Objects.requireNonNull(f, "f is null");
             return f.apply(this);
         }
 
diff --git a/src/main/java/io/vavr/control/Option.java b/src/main/java/io/vavr/control/Option.java
index b549c12da..29fc22a97 100644
--- a/src/main/java/io/vavr/control/Option.java
+++ b/src/main/java/io/vavr/control/Option.java
@@ -102,7 +102,6 @@ public static <T> Option<T> of(T value) {
      * @throws NullPointerException if {@code values} is null
      */
     public static <T> Option<Seq<T>> sequence(Iterable<? extends Option<? extends T>> values) {
-        Objects.requireNonNull(values, "values is null");
         Vector<T> vector = Vector.empty();
         for (Option<? extends T> value : values) {
             if (value.isEmpty()) {
@@ -140,8 +139,6 @@ public static <T> Option<Seq<T>> sequence(Iterable<? extends Option<? extends T>
      * @throws NullPointerException if values or f is null.
      */
     public static <T, U> Option<Seq<U>> traverse(Iterable<? extends T> values, Function<? super T, ? extends Option<? extends U>> mapper) {
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequence(Iterator.ofAll(values).map(mapper));
     }
 
@@ -223,7 +220,6 @@ public static <T> Option<T> narrow(Option<? extends T> option) {
      * @throws NullPointerException if the given {@code supplier} is null
      */
     public static <T> Option<T> when(boolean condition, Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return condition ? some(supplier.get()) : none();
     }
 
@@ -268,7 +264,6 @@ public static <T> Option<T> when(boolean condition, T value) {
      */
     @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
     public static <T> Option<T> ofOptional(Optional<? extends T> optional) {
-        Objects.requireNonNull(optional, "optional is null");
         return optional.<Option<T>>map(Option::of).orElseGet(Option::none);
     }
 
@@ -292,7 +287,6 @@ public static <T> Option<T> ofOptional(Optional<? extends T> optional) {
      * @throws NullPointerException if {@code partialFunction} is null
      */
     public final <R> Option<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
         return flatMap(partialFunction.lift());
     }
 
@@ -329,7 +323,6 @@ public final <R> Option<R> collect(PartialFunction<? super T, ? extends R> parti
      * @return this {@code Option}
      */
     public final Option<T> onEmpty(Runnable action) {
-        Objects.requireNonNull(action, "action is null");
         if (isEmpty()) {
             action.run();
         }
@@ -468,7 +461,6 @@ public final T getOrElse(T other) {
      */
     @SuppressWarnings("unchecked")
     public final Option<T> orElse(Option<? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         return isEmpty() ? (Option<T>) other : this;
     }
 
@@ -490,7 +482,6 @@ public final Option<T> orElse(Option<? extends T> other) {
      */
     @SuppressWarnings("unchecked")
     public final Option<T> orElse(Supplier<? extends Option<? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isEmpty() ? (Option<T>) supplier.get() : this;
     }
 
@@ -531,7 +522,6 @@ public final T orNull() {
      */
     @Override
     public final T getOrElse(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isEmpty() ? supplier.get() : get();
     }
 
@@ -555,7 +545,6 @@ public final T getOrElse(Supplier<? extends T> supplier) {
      */
     @Override
     public final <X extends Throwable> T getOrElseThrow(Supplier<X> exceptionSupplier) throws X {
-        Objects.requireNonNull(exceptionSupplier, "exceptionSupplier is null");
         if (isEmpty()) {
             throw exceptionSupplier.get();
         } else {
@@ -584,7 +573,6 @@ public final <X extends Throwable> T getOrElseThrow(Supplier<X> exceptionSupplie
      * @return {@code Some(value)} or {@code None} as specified
      */
     public final Option<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return isEmpty() || predicate.test(get()) ? this : none();
     }
 
@@ -609,7 +597,6 @@ public final Option<T> filter(Predicate<? super T> predicate) {
      * @return {@code Some(value)} or {@code None} as specified
      */
     public final Option<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
@@ -635,7 +622,6 @@ public final Option<T> filterNot(Predicate<? super T> predicate) {
      */
     @SuppressWarnings("unchecked")
     public final <U> Option<U> flatMap(Function<? super T, ? extends Option<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? none() : (Option<U>) mapper.apply(get());
     }
 
@@ -658,7 +644,6 @@ public final <U> Option<U> flatMap(Function<? super T, ? extends Option<? extend
      */
     @Override
     public final <U> Option<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isEmpty() ? none() : some(mapper.apply(get()));
     }
 
@@ -694,8 +679,6 @@ public final <U> U fold(Supplier<? extends U> ifNone, Function<? super T, ? exte
      * @return this instance
      */
     public final Option<T> peek(Runnable noneAction, Consumer<? super T> someAction) {
-        Objects.requireNonNull(noneAction, "noneAction is null");
-        Objects.requireNonNull(someAction, "someAction is null");
 
         if (isEmpty()) {
             noneAction.run();
@@ -724,7 +707,6 @@ public final Option<T> peek(Runnable noneAction, Consumer<? super T> someAction)
      */
     @Override
     public final Option<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isDefined()) {
             action.accept(get());
         }
@@ -750,7 +732,6 @@ public final Option<T> peek(Consumer<? super T> action) {
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Option<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
diff --git a/src/main/java/io/vavr/control/Try.java b/src/main/java/io/vavr/control/Try.java
index 25eee1293..c24db7de7 100644
--- a/src/main/java/io/vavr/control/Try.java
+++ b/src/main/java/io/vavr/control/Try.java
@@ -86,7 +86,6 @@ private Try() {
      * exception occurs calling {@code supplier.apply()}.
      */
     public static <T> Try<T> of(CheckedFunction0<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         try {
             return new Success<>(supplier.apply());
         } catch (Throwable t) {
@@ -112,7 +111,6 @@ public static <T> Try<T> of(CheckedFunction0<? extends T> supplier) {
      * exception occurs calling {@code supplier.get()}.
      */
     public static <T> Try<T> ofSupplier(Supplier<? extends T> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return of(supplier::get);
     }
 
@@ -135,7 +133,6 @@ public static <T> Try<T> ofSupplier(Supplier<? extends T> supplier) {
      * exception occurs calling {@code callable.call()}.
      */
     public static <T> Try<T> ofCallable(Callable<? extends T> callable) {
-        Objects.requireNonNull(callable, "callable is null");
         return of(callable::call);
     }
 
@@ -157,7 +154,6 @@ public static <T> Try<T> ofCallable(Callable<? extends T> callable) {
      * calling {@code runnable.run()}.
      */
     public static Try<Void> run(CheckedRunnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         try {
             runnable.run();
             return new Success<>(null); // null represents the absence of an value, i.e. Void
@@ -184,7 +180,6 @@ public static Try<Void> run(CheckedRunnable runnable) {
      * calling {@code runnable.run()}.
      */
     public static Try<Void> runRunnable(Runnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         return run(runnable::run);
     }
 
@@ -211,7 +206,6 @@ public static Try<Void> runRunnable(Runnable runnable) {
      * @throws NullPointerException if {@code values} is null
      */
     public static <T> Try<Seq<T>> sequence(Iterable<? extends Try<? extends T>> values) {
-        Objects.requireNonNull(values, "values is null");
         Vector<T> vector = Vector.empty();
         for (Try<? extends T> value : values) {
             if (value.isFailure()) {
@@ -244,8 +238,6 @@ public static <T> Try<Seq<T>> sequence(Iterable<? extends Try<? extends T>> valu
      * @throws NullPointerException if values or f is null.
      */
     public static <T, U> Try<Seq<U>> traverse(Iterable<? extends T> values, Function<? super T, ? extends Try<? extends U>> mapper) {
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequence(Iterator.ofAll(values).map(mapper));
     }
 
@@ -310,7 +302,6 @@ public static <T> Try<T> narrow(Try<? extends T> t) {
      * @throws NullPointerException if {@code consumer} is null
      */
     public final Try<T> andThen(Consumer<? super T> consumer) {
-        Objects.requireNonNull(consumer, "consumer is null");
         return andThenTry(consumer::accept);
     }
 
@@ -333,7 +324,6 @@ public final Try<T> andThen(Consumer<? super T> consumer) {
      * @throws NullPointerException if {@code consumer} is null
      */
     public final Try<T> andThenTry(CheckedConsumer<? super T> consumer) {
-        Objects.requireNonNull(consumer, "consumer is null");
         if (isFailure()) {
             return this;
         } else {
@@ -355,7 +345,6 @@ public final Try<T> andThenTry(CheckedConsumer<? super T> consumer) {
      * @throws NullPointerException if {@code runnable} is null
      */
     public final Try<T> andThen(Runnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         return andThenTry(runnable::run);
     }
 
@@ -392,7 +381,6 @@ public final Try<T> andThen(Runnable runnable) {
      * @throws NullPointerException if {@code runnable} is null
      */
     public final Try<T> andThenTry(CheckedRunnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         if (isFailure()) {
             return this;
         } else {
@@ -425,7 +413,6 @@ public final Try<T> andThenTry(CheckedRunnable runnable) {
      */
     @SuppressWarnings("unchecked")
     public final <R> Try<R> collect(PartialFunction<? super T, ? extends R> partialFunction){
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
         return filter(partialFunction::isDefinedAt).map(partialFunction);
     }
 
@@ -453,8 +440,6 @@ public final Try<Throwable> failed() {
      * @throws NullPointerException if {@code predicate} or {@code throwableSupplier} is null
      */
     public final Try<T> filter(Predicate<? super T> predicate, Supplier<? extends Throwable> throwableSupplier) {
-        Objects.requireNonNull(predicate, "predicate is null");
-        Objects.requireNonNull(throwableSupplier, "throwableSupplier is null");
         return filterTry(predicate::test, throwableSupplier);
     }
 
@@ -468,8 +453,6 @@ public final Try<T> filter(Predicate<? super T> predicate, Supplier<? extends Th
      * @throws NullPointerException if {@code predicate} or {@code errorProvider} is null
      */
     public final Try<T> filter(Predicate<? super T> predicate, Function<? super T, ? extends Throwable> errorProvider) {
-        Objects.requireNonNull(predicate, "predicate is null");
-        Objects.requireNonNull(errorProvider, "errorProvider is null");
         return filterTry(predicate::test, errorProvider::apply);
     }
 
@@ -481,7 +464,6 @@ public final Try<T> filter(Predicate<? super T> predicate, Function<? super T, ?
      * @throws NullPointerException if {@code predicate} is null
      */
     public final Try<T> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterTry(predicate::test);
     }
 
@@ -494,7 +476,6 @@ public final Try<T> filter(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} or {@code throwableSupplier} is null
      */
     public final Try<T> filterNot(Predicate<? super T> predicate, Supplier<? extends Throwable> throwableSupplier) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate(), throwableSupplier);
     }
 
@@ -508,7 +489,6 @@ public final Try<T> filterNot(Predicate<? super T> predicate, Supplier<? extends
      * @throws NullPointerException if {@code predicate} or {@code errorProvider} is null
      */
     public final Try<T> filterNot(Predicate<? super T> predicate, Function<? super T, ? extends Throwable> errorProvider) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate(), errorProvider);
     }
 
@@ -521,7 +501,6 @@ public final Try<T> filterNot(Predicate<? super T> predicate, Function<? super T
      * @throws NullPointerException if {@code predicate} is null
      */
     public final Try<T> filterNot(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filter(predicate.negate());
     }
 
@@ -538,8 +517,6 @@ public final Try<T> filterNot(Predicate<? super T> predicate) {
      * @throws NullPointerException if {@code predicate} or {@code throwableSupplier} is null
      */
     public final Try<T> filterTry(CheckedPredicate<? super T> predicate, Supplier<? extends Throwable> throwableSupplier) {
-        Objects.requireNonNull(predicate, "predicate is null");
-        Objects.requireNonNull(throwableSupplier, "throwableSupplier is null");
 
         if (isFailure()) {
             return this;
@@ -569,8 +546,6 @@ public final Try<T> filterTry(CheckedPredicate<? super T> predicate, Supplier<?
      * @throws NullPointerException if {@code predicate} or {@code errorProvider} is null
      */
     public final Try<T> filterTry(CheckedPredicate<? super T> predicate, CheckedFunction1<? super T, ? extends Throwable> errorProvider) {
-        Objects.requireNonNull(predicate, "predicate is null");
-        Objects.requireNonNull(errorProvider, "errorProvider is null");
         return flatMapTry(t -> predicate.test(t) ? this : failure(errorProvider.apply(t)));
     }
 
@@ -585,7 +560,6 @@ public final Try<T> filterTry(CheckedPredicate<? super T> predicate, CheckedFunc
      * @throws NullPointerException if {@code predicate} is null
      */
     public final Try<T> filterTry(CheckedPredicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return filterTry(predicate, () -> new NoSuchElementException("Predicate does not hold for " + get()));
     }
 
@@ -598,7 +572,6 @@ public final Try<T> filterTry(CheckedPredicate<? super T> predicate) {
      * @throws NullPointerException if {@code mapper} is null
      */
     public final <U> Try<U> flatMap(Function<? super T, ? extends Try<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return flatMapTry((CheckedFunction1<T, Try<? extends U>>) mapper::apply);
     }
 
@@ -612,7 +585,6 @@ public final <U> Try<U> flatMap(Function<? super T, ? extends Try<? extends U>>
      */
     @SuppressWarnings("unchecked")
     public final <U> Try<U> flatMapTry(CheckedFunction1<? super T, ? extends Try<? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isFailure()) {
             return (Failure<U>) this;
         } else {
@@ -711,7 +683,6 @@ public final Iterator<T> iterator() {
      */
     @Override
     public final <U> Try<U> map(Function<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return mapTry(mapper::apply);
     }
 
@@ -755,7 +726,6 @@ public final Try<T> mapFailure(Match.Case<? extends Throwable, ? extends Throwab
      */
     @SuppressWarnings("unchecked")
     public final <U> Try<U> mapTry(CheckedFunction1<? super T, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         if (isFailure()) {
             return (Failure<U>) this;
         } else {
@@ -783,7 +753,6 @@ public final <U> Try<U> mapTry(CheckedFunction1<? super T, ? extends U> mapper)
      * @throws NullPointerException if {@code action} is null
      */
     public final Try<T> onFailure(Consumer<? super Throwable> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isFailure()) {
             action.accept(getCause());
         }
@@ -811,8 +780,6 @@ public final Try<T> onFailure(Consumer<? super Throwable> action) {
      */
     @SuppressWarnings("unchecked")
     public final <X extends Throwable> Try<T> onFailure(Class<X> exceptionType, Consumer<? super X> action) {
-        Objects.requireNonNull(exceptionType, "exceptionType is null");
-        Objects.requireNonNull(action, "action is null");
         if (isFailure() && exceptionType.isAssignableFrom(getCause().getClass())) {
             action.accept((X) getCause());
         }
@@ -835,7 +802,6 @@ public final <X extends Throwable> Try<T> onFailure(Class<X> exceptionType, Cons
      * @throws NullPointerException if {@code action} is null
      */
     public final Try<T> onSuccess(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isSuccess()) {
             action.accept(get());
         }
@@ -844,18 +810,15 @@ public final Try<T> onSuccess(Consumer<? super T> action) {
 
     @SuppressWarnings("unchecked")
     public final Try<T> orElse(Try<? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         return isSuccess() ? this : (Try<T>) other;
     }
 
     @SuppressWarnings("unchecked")
     public final Try<T> orElse(Supplier<? extends Try<? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isSuccess() ? this : (Try<T>) supplier.get();
     }
 
     public final T getOrElseGet(Function<? super Throwable, ? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         if (isFailure()) {
             return other.apply(getCause());
         } else {
@@ -864,14 +827,12 @@ public final T getOrElseGet(Function<? super Throwable, ? extends T> other) {
     }
 
     public final void orElseRun(Consumer<? super Throwable> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isFailure()) {
             action.accept(getCause());
         }
     }
 
     public final <X extends Throwable> T getOrElseThrow(Function<? super Throwable, X> exceptionProvider) throws X {
-        Objects.requireNonNull(exceptionProvider, "exceptionProvider is null");
         if (isFailure()) {
             throw exceptionProvider.apply(getCause());
         } else {
@@ -903,8 +864,6 @@ public final <X> X fold(Function<? super Throwable, ? extends X> ifFail, Functio
      * @return this {@code Try}
      */
     public final Try<T> peek(Consumer<? super Throwable> failureAction, Consumer<? super T> successAction) {
-        Objects.requireNonNull(failureAction, "failureAction is null");
-        Objects.requireNonNull(successAction, "successAction is null");
 
         if (isFailure()) {
             failureAction.accept(getCause());
@@ -924,7 +883,6 @@ public final Try<T> peek(Consumer<? super Throwable> failureAction, Consumer<? s
      */
     @Override
     public final Try<T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isSuccess()) {
             action.accept(get());
         }
@@ -957,8 +915,6 @@ public final Try<T> peek(Consumer<? super T> action) {
      */
     @SuppressWarnings("unchecked")
     public final <X extends Throwable> Try<T> recover(Class<X> exceptionType, Function<? super X, ? extends T> f) {
-        Objects.requireNonNull(exceptionType, "exceptionType is null");
-        Objects.requireNonNull(f, "f is null");
         if (isFailure()) {
             final Throwable cause = getCause();
             if (exceptionType.isAssignableFrom(cause.getClass())) {
@@ -995,8 +951,6 @@ public final <X extends Throwable> Try<T> recover(Class<X> exceptionType, Functi
      */
     @SuppressWarnings("unchecked")
     public final <X extends Throwable> Try<T> recoverWith(Class<X> exceptionType, Function<? super X, Try<? extends T>> f){
-        Objects.requireNonNull(exceptionType, "exceptionType is null");
-        Objects.requireNonNull(f, "f is null");
         if(isFailure()){
             final Throwable cause = getCause();
             if (exceptionType.isAssignableFrom(cause.getClass())) {
@@ -1034,8 +988,6 @@ public final <X extends Throwable> Try<T> recoverWith(Class<X> exceptionType, Fu
      * @throws NullPointerException if {@code exceptionType} or {@code recovered} is null
      */
     public final <X extends Throwable> Try<T> recoverWith(Class<X> exceptionType,  Try<? extends T> recovered){
-        Objects.requireNonNull(exceptionType, "exeptionType is null");
-        Objects.requireNonNull(recovered, "recovered is null");
         return (isFailure() && exceptionType.isAssignableFrom(getCause().getClass()))
                 ? narrow(recovered)
                 : this;
@@ -1065,7 +1017,6 @@ public final <X extends Throwable> Try<T> recoverWith(Class<X> exceptionType,  T
      * @throws NullPointerException if {@code exception} is null
      */
     public final <X extends Throwable> Try<T> recover(Class<X> exceptionType, T value) {
-        Objects.requireNonNull(exceptionType, "exceptionType is null");
         return (isFailure() && exceptionType.isAssignableFrom(getCause().getClass()))
                ? Try.success(value)
                : this;
@@ -1088,7 +1039,6 @@ public final <X extends Throwable> Try<T> recover(Class<X> exceptionType, T valu
      * @throws NullPointerException if {@code f} is null
      */
     public final Try<T> recover(Function<? super Throwable, ? extends T> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isFailure()) {
             return Try.of(() -> f.apply(getCause()));
         } else {
@@ -1115,7 +1065,6 @@ public final Try<T> recover(Function<? super Throwable, ? extends T> f) {
      */
     @SuppressWarnings("unchecked")
     public final Try<T> recoverWith(Function<? super Throwable, ? extends Try<? extends T>> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isFailure()) {
             try {
                 return (Try<T>) f.apply(getCause());
@@ -1163,7 +1112,6 @@ public final Validation<Throwable, T> toValidation() {
      * @throws NullPointerException if the given {@code throwableMapper} is null.
      */
     public final <U> Validation<U, T> toValidation(Function<? super Throwable, ? extends U> throwableMapper) {
-        Objects.requireNonNull(throwableMapper, "throwableMapper is null");
         if (isFailure()) {
             return Validation.invalid(throwableMapper.apply(getCause()));
         } else {
@@ -1180,7 +1128,6 @@ public final <U> Validation<U, T> toValidation(Function<? super Throwable, ? ext
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Try<T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -1192,7 +1139,6 @@ public final <U> U transform(Function<? super Try<T>, ? extends U> f) {
      * @throws NullPointerException if {@code runnable} is null
      */
     public final Try<T> andFinally(Runnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         return andFinallyTry(runnable::run);
     }
 
@@ -1204,7 +1150,6 @@ public final Try<T> andFinally(Runnable runnable) {
      * @throws NullPointerException if {@code runnable} is null
      */
     public final Try<T> andFinallyTry(CheckedRunnable runnable) {
-        Objects.requireNonNull(runnable, "runnable is null");
         try {
             runnable.run();
             return this;
@@ -1302,7 +1247,6 @@ public static final class Failure<T> extends Try<T> implements Serializable {
          * @throws Throwable            if the given {@code cause} is fatal, i.e. non-recoverable
          */
         private Failure(Throwable cause) {
-            Objects.requireNonNull(cause, "cause is null");
             if (isFatal(cause)) {
                 sneakyThrow(cause);
             }
diff --git a/src/main/java/io/vavr/control/Validation.java b/src/main/java/io/vavr/control/Validation.java
index f8813acea..9be3053fa 100644
--- a/src/main/java/io/vavr/control/Validation.java
+++ b/src/main/java/io/vavr/control/Validation.java
@@ -113,7 +113,6 @@ public static <E, T> Validation<E, T> valid(T value) {
      * @throws NullPointerException if error is null
      */
     public static <E, T> Validation<E, T> invalid(E error) {
-        Objects.requireNonNull(error, "error is null");
         return new Invalid<>(error);
     }
 
@@ -136,7 +135,6 @@ public static <E, T> Validation<E, T> invalid(E error) {
      * @throws NullPointerException if either is null
      */
     public static <E, T> Validation<E, T> fromEither(Either<E, T> either) {
-        Objects.requireNonNull(either, "either is null");
         return either.isRight() ? valid(either.get()) : invalid(either.getLeft());
     }
 
@@ -158,7 +156,6 @@ public static <E, T> Validation<E, T> fromEither(Either<E, T> either) {
      * @throws NullPointerException if {@code t} is null
      */
     public static <T> Validation<Throwable, T> fromTry(Try<? extends T> t) {
-        Objects.requireNonNull(t, "t is null");
         return t.isSuccess() ? valid(t.get()) : invalid(t.getCause());
     }
 
@@ -184,7 +181,6 @@ public static <T> Validation<Throwable, T> fromTry(Try<? extends T> t) {
      * @throws NullPointerException if values is null
      */
     public static <E, T> Validation<Seq<E>, Seq<T>> sequence(Iterable<? extends Validation<? extends Seq<? extends E>, ? extends T>> values) {
-        Objects.requireNonNull(values, "values is null");
         List<E> errors = List.empty();
         List<T> list = List.empty();
         for (Validation<? extends Seq<? extends E>, ? extends T> value : values) {
@@ -199,7 +195,6 @@ public static <E, T> Validation<Seq<E>, Seq<T>> sequence(Iterable<? extends Vali
 
     /**
      * A wrapper to {@link #all(Traversable)}.
-     * <p/>
      * Usage example :
      *
      * <pre>{@code
@@ -252,7 +247,6 @@ public static <E, T> Validation<Seq<E>, T> all(Traversable<? extends Validation
      * @throws NullPointerException if {@code f} is null
      */
     public final <U> U transform(Function<? super Validation<E, T>, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return f.apply(this);
     }
 
@@ -276,8 +270,6 @@ public final <U> U transform(Function<? super Validation<E, T>, ? extends U> f)
      * @throws NullPointerException if values or f is null.
      */
     public static <E, T, U> Validation<Seq<E>, Seq<U>> traverse(Iterable<? extends T> values, Function<? super T, ? extends Validation<? extends Seq<? extends E>, ? extends U>> mapper) {
-        Objects.requireNonNull(values, "values is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return sequence(Iterator.ofAll(values).map(mapper));
     }
 
@@ -323,8 +315,6 @@ public static <E, T> Validation<E, T> narrow(Validation<? extends E, ? extends T
      * @throws NullPointerException if validation1 or validation2 is null
      */
     public static <E, T1, T2> Builder<E, T1, T2> combine(Validation<E, T1> validation1, Validation<E, T2> validation2) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
         return new Builder<>(validation1, validation2);
     }
 
@@ -351,9 +341,6 @@ public static <E, T1, T2> Builder<E, T1, T2> combine(Validation<E, T1> validatio
      * @throws NullPointerException if validation1, validation2 or validation3 is null
      */
     public static <E, T1, T2, T3> Builder3<E, T1, T2, T3> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
         return new Builder3<>(validation1, validation2, validation3);
     }
 
@@ -383,10 +370,6 @@ public static <E, T1, T2, T3> Builder3<E, T1, T2, T3> combine(Validation<E, T1>
      * @throws NullPointerException if validation1, validation2, validation3 or validation4 is null
      */
     public static <E, T1, T2, T3, T4> Builder4<E, T1, T2, T3, T4> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3, Validation<E, T4> validation4) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
-        Objects.requireNonNull(validation4, "validation4 is null");
         return new Builder4<>(validation1, validation2, validation3, validation4);
     }
 
@@ -420,11 +403,6 @@ public static <E, T1, T2, T3, T4> Builder4<E, T1, T2, T3, T4> combine(Validation
      * @throws NullPointerException if validation1, validation2, validation3, validation4 or validation5 is null
      */
     public static <E, T1, T2, T3, T4, T5> Builder5<E, T1, T2, T3, T4, T5> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3, Validation<E, T4> validation4, Validation<E, T5> validation5) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
-        Objects.requireNonNull(validation4, "validation4 is null");
-        Objects.requireNonNull(validation5, "validation5 is null");
         return new Builder5<>(validation1, validation2, validation3, validation4, validation5);
     }
 
@@ -460,12 +438,6 @@ public static <E, T1, T2, T3, T4, T5> Builder5<E, T1, T2, T3, T4, T5> combine(Va
      * @throws NullPointerException if validation1, validation2, validation3, validation4, validation5 or validation6 is null
      */
     public static <E, T1, T2, T3, T4, T5, T6> Builder6<E, T1, T2, T3, T4, T5, T6> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3, Validation<E, T4> validation4, Validation<E, T5> validation5, Validation<E, T6> validation6) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
-        Objects.requireNonNull(validation4, "validation4 is null");
-        Objects.requireNonNull(validation5, "validation5 is null");
-        Objects.requireNonNull(validation6, "validation6 is null");
         return new Builder6<>(validation1, validation2, validation3, validation4, validation5, validation6);
     }
 
@@ -504,13 +476,6 @@ public static <E, T1, T2, T3, T4, T5, T6> Builder6<E, T1, T2, T3, T4, T5, T6> co
      * @throws NullPointerException if validation1, validation2, validation3, validation4, validation5, validation6 or validation7 is null
      */
     public static <E, T1, T2, T3, T4, T5, T6, T7> Builder7<E, T1, T2, T3, T4, T5, T6, T7> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3, Validation<E, T4> validation4, Validation<E, T5> validation5, Validation<E, T6> validation6, Validation<E, T7> validation7) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
-        Objects.requireNonNull(validation4, "validation4 is null");
-        Objects.requireNonNull(validation5, "validation5 is null");
-        Objects.requireNonNull(validation6, "validation6 is null");
-        Objects.requireNonNull(validation7, "validation7 is null");
         return new Builder7<>(validation1, validation2, validation3, validation4, validation5, validation6, validation7);
     }
 
@@ -552,14 +517,6 @@ public static <E, T1, T2, T3, T4, T5, T6, T7> Builder7<E, T1, T2, T3, T4, T5, T6
      * @throws NullPointerException if validation1, validation2, validation3, validation4, validation5, validation6, validation7 or validation8 is null
      */
     public static <E, T1, T2, T3, T4, T5, T6, T7, T8> Builder8<E, T1, T2, T3, T4, T5, T6, T7, T8> combine(Validation<E, T1> validation1, Validation<E, T2> validation2, Validation<E, T3> validation3, Validation<E, T4> validation4, Validation<E, T5> validation5, Validation<E, T6> validation6, Validation<E, T7> validation7, Validation<E, T8> validation8) {
-        Objects.requireNonNull(validation1, "validation1 is null");
-        Objects.requireNonNull(validation2, "validation2 is null");
-        Objects.requireNonNull(validation3, "validation3 is null");
-        Objects.requireNonNull(validation4, "validation4 is null");
-        Objects.requireNonNull(validation5, "validation5 is null");
-        Objects.requireNonNull(validation6, "validation6 is null");
-        Objects.requireNonNull(validation7, "validation7 is null");
-        Objects.requireNonNull(validation8, "validation8 is null");
         return new Builder8<>(validation1, validation2, validation3, validation4, validation5, validation6, validation7, validation8);
     }
 
@@ -592,7 +549,6 @@ public static <E, T1, T2, T3, T4, T5, T6, T7, T8> Builder8<E, T1, T2, T3, T4, T5
      */
     @SuppressWarnings("unchecked")
     public final Validation<E, T> orElse(Validation<? extends E, ? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         return isValid() ? this : (Validation<E, T>) other;
     }
 
@@ -610,7 +566,6 @@ public final Validation<E, T> orElse(Validation<? extends E, ? extends T> other)
      */
     @SuppressWarnings("unchecked")
     public final Validation<E, T> orElse(Supplier<Validation<? extends E, ? extends T>> supplier) {
-        Objects.requireNonNull(supplier, "supplier is null");
         return isValid() ? this : (Validation<E, T>) supplier.get();
     }
 
@@ -644,7 +599,6 @@ public final boolean isEmpty() {
      * provided by {@code other} by applying the error.
      */
     public final T getOrElseGet(Function<? super E, ? extends T> other) {
-        Objects.requireNonNull(other, "other is null");
         if (isValid()) {
             return get();
         } else {
@@ -685,7 +639,6 @@ public final Either<E, T> toEither() {
      */
     @Override
     public final void forEach(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
         if (isValid()) {
             action.accept(get());
         }
@@ -708,8 +661,6 @@ public final void forEach(Consumer<? super T> action) {
      * @throws NullPointerException if one of the given mappers {@code ifInvalid} or {@code ifValid} is null
      */
     public final <U> U fold(Function<? super E, ? extends U> ifInvalid, Function<? super T, ? extends U> ifValid) {
-        Objects.requireNonNull(ifInvalid, "ifInvalid is null");
-        Objects.requireNonNull(ifValid, "ifValid is null");
         return isValid() ? ifValid.apply(get()) : ifInvalid.apply(getError());
     }
 
@@ -732,7 +683,6 @@ public final <U> U fold(Function<? super E, ? extends U> ifInvalid, Function<? s
      * @throws X if the projected Validation is an Invalid
      */
     public final <X extends Throwable> T getOrElseThrow(Function<? super E, X> exceptionFunction) throws X {
-      Objects.requireNonNull(exceptionFunction, "exceptionFunction is null");
       if (isValid()) {
         return get();
       } else {
@@ -758,7 +708,6 @@ public final Validation<T, E> swap() {
 
     @Override
     public final <U> Validation<E, U> map(Function<? super T, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isInvalid()) {
             return Validation.invalid(this.getError());
         } else {
@@ -782,8 +731,6 @@ public final <U> Validation<E, U> map(Function<? super T, ? extends U> f) {
      * @throws NullPointerException if invalidMapper or validMapper is null
      */
     public final <E2, T2> Validation<E2, T2> bimap(Function<? super E, ? extends E2> errorMapper, Function<? super T, ? extends T2> valueMapper) {
-        Objects.requireNonNull(errorMapper, "errorMapper is null");
-        Objects.requireNonNull(valueMapper, "valueMapper is null");
         if (isInvalid()) {
             final E error = this.getError();
             return Validation.invalid(errorMapper.apply(error));
@@ -803,7 +750,6 @@ public final <E2, T2> Validation<E2, T2> bimap(Function<? super E, ? extends E2>
      * @throws NullPointerException if mapping operation f is null
      */
     public final <U> Validation<U, T> mapError(Function<? super E, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         if (isInvalid()) {
             final E error = this.getError();
             return Validation.invalid(f.apply(error));
@@ -813,7 +759,6 @@ public final <U> Validation<U, T> mapError(Function<? super E, ? extends U> f) {
     }
 
     public final <U> Validation<Seq<E>, U> ap(Validation<Seq<E>, ? extends Function<? super T, ? extends U>> validation) {
-        Objects.requireNonNull(validation, "validation is null");
         if (isValid()) {
             if (validation.isValid()) {
                 final Function<? super T, ? extends U> f = validation.get();
@@ -850,13 +795,11 @@ public final <U> Builder<E, T, U> combine(Validation<E, U> validation) {
     // -- Implementation of Value
 
     public final Option<Validation<E, T>> filter(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return isInvalid() || predicate.test(get()) ? Option.some(this) : Option.none();
     }
 
     @SuppressWarnings("unchecked")
     public final <U> Validation<E, U> flatMap(Function<? super T, ? extends Validation<E, ? extends U>> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return isInvalid() ? (Validation<E, U>) this : (Validation<E, U>) mapper.apply(get());
     }
 
@@ -868,8 +811,6 @@ public final <U> Validation<E, U> flatMap(Function<? super T, ? extends Validati
      * @return this {@code Validation}
      */
     public final Validation<E, T> peek(Consumer<? super E> invalidAction, Consumer<? super T> validAction) {
-        Objects.requireNonNull(invalidAction, "invalidAction is null");
-        Objects.requireNonNull(validAction, "validAction is null");
 
         if(isInvalid()) {
             invalidAction.accept(getError());
@@ -882,7 +823,6 @@ public final Validation<E, T> peek(Consumer<? super E> invalidAction, Consumer<?
 
     @Override
     public final Validation<E, T> peek(Consumer<? super T> action) {
-        Objects.requireNonNull(action, "action is null");
 
         if (isValid()) {
             action.accept(get());
@@ -891,7 +831,6 @@ public final Validation<E, T> peek(Consumer<? super T> action) {
     }
 
     public final Validation<E, T> peekError(Consumer<? super E> action) {
-        Objects.requireNonNull(action, "action is null");
 
         if (isInvalid()) {
             action.accept(getError());
diff --git a/src/test/java/io/vavr/CheckedConsumerTest.java b/src/test/java/io/vavr/CheckedConsumerTest.java
index 23c9ca408..6c7a32bd6 100644
--- a/src/test/java/io/vavr/CheckedConsumerTest.java
+++ b/src/test/java/io/vavr/CheckedConsumerTest.java
@@ -81,9 +81,10 @@ public void shouldApplyThrowingCheckedConsumer() {
     // -- andThen
 
     @Test
-    public void shouldThrowWhenComposingCheckedConsumerUsingAndThenWithNullParameter() {
+    public void shouldThrowWhenComposingCheckedConsumerUsingAndThenWithNullParameterButOnlyUponInvokingTheResultingConsumer() {
         final CheckedConsumer<?> f = t -> {};
-        assertThatThrownBy(() -> f.andThen(null)).isInstanceOf(NullPointerException.class);
+        final CheckedConsumer<?> fAndThenNull = f.andThen(null);
+        assertThatThrownBy(() -> fAndThenNull.accept(null)).isInstanceOf(NullPointerException.class);
     }
 
     @Test
diff --git a/src/test/java/io/vavr/JavaCollections.java b/src/test/java/io/vavr/JavaCollections.java
index 95245658a..069342ceb 100644
--- a/src/test/java/io/vavr/JavaCollections.java
+++ b/src/test/java/io/vavr/JavaCollections.java
@@ -35,7 +35,6 @@ private JavaCollections() {
 
     @SuppressWarnings("unchecked")
     static <K, V> Map<K, V> javaMap(Object... pairs) {
-        Objects.requireNonNull(pairs, "pairs is null");
         if ((pairs.length & 1) != 0) {
             throw new IllegalArgumentException("Odd length of key-value pairs list");
         }
@@ -48,7 +47,6 @@ static <K, V> Map<K, V> javaMap(Object... pairs) {
 
     @SuppressWarnings("unchecked")
     static <T> Set<T> javaSet(T... elements) {
-        Objects.requireNonNull(elements, "elements is null");
         final Set<T> set = new HashSet<>();
         Collections.addAll(set, elements);
         return set;
diff --git a/src/test/java/io/vavr/LazyTest.java b/src/test/java/io/vavr/LazyTest.java
index 8002ef7bd..7980ba7b5 100644
--- a/src/test/java/io/vavr/LazyTest.java
+++ b/src/test/java/io/vavr/LazyTest.java
@@ -90,11 +90,6 @@ public void shouldNotChangeLazy() {
         assertThat(Lazy.of(expected)).isSameAs(expected);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowOnNullSupplier() {
-        Lazy.of(null);
-    }
-
     @Test
     public void shouldMemoizeValues() {
         final Lazy<Double> testee = Lazy.of(Math::random);
@@ -219,12 +214,7 @@ public void shouldCreateLazyProxy() {
         assertThat(evaluated[0]).isEqualTo("Yay!");
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenCreatingLazyProxyAndSupplierIsNull() {
-        Lazy.val(null, CharSequence.class);
-    }
-
-    @Test(expected = NullPointerException.class)
+    @Test(expected = Exception.class)
     public void shouldThrowWhenCreatingLazyProxyAndTypeIsNull() {
         Lazy.val(() -> "", null);
     }
diff --git a/src/test/java/io/vavr/collection/AbstractMapTest.java b/src/test/java/io/vavr/collection/AbstractMapTest.java
index 2a89a1b0c..afa81b847 100644
--- a/src/test/java/io/vavr/collection/AbstractMapTest.java
+++ b/src/test/java/io/vavr/collection/AbstractMapTest.java
@@ -933,11 +933,13 @@ public void shouldZipNonNilsOfSameSize() {
                 Stream.of(Tuple.of(Tuple.of(0, 0), 5), Tuple.of(Tuple.of(1, 1), 6), Tuple.of(Tuple.of(2, 2), 7)));
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowIfZipWithThatIsNull() {
-        emptyMap().zip(null);
+    @Override
+    @Test
+    public void shouldIgnoreNullIfThereIsNothingToZip() {
+        assertThat(emptyMap().zip(null)).isEmpty();
     }
 
+
     // -- zipWithIndex
 
     @Test
diff --git a/src/test/java/io/vavr/collection/AbstractMultimapTest.java b/src/test/java/io/vavr/collection/AbstractMultimapTest.java
index f06cf6b04..fd1fe8cbe 100644
--- a/src/test/java/io/vavr/collection/AbstractMultimapTest.java
+++ b/src/test/java/io/vavr/collection/AbstractMultimapTest.java
@@ -1063,9 +1063,10 @@ public void shouldZipNonNilsOfSameSize() {
                 Stream.of(Tuple.of(Tuple.of(0, 0), 5), Tuple.of(Tuple.of(1, 1), 6), Tuple.of(Tuple.of(2, 2), 7)));
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowIfZipWithThatIsNull() {
-        emptyMap().zip(null);
+    @Override
+    @Test
+    public void shouldIgnoreNullIfThereIsNothingToZip() {
+        assertThat(emptyMap().zip(null)).isEmpty();
     }
 
     // -- zipWithIndex
diff --git a/src/test/java/io/vavr/collection/AbstractTraversableTest.java b/src/test/java/io/vavr/collection/AbstractTraversableTest.java
index d7ae502c5..df3c12a49 100644
--- a/src/test/java/io/vavr/collection/AbstractTraversableTest.java
+++ b/src/test/java/io/vavr/collection/AbstractTraversableTest.java
@@ -300,10 +300,8 @@ public void shouldCalculateAverageOfFloatPositiveAndNegativeInfinity() {
     // -- collect
 
     @Test
-    public void shouldThrowOnCollectWhenPartialFunctionIsNull() {
-        assertThatThrownBy(() -> empty().collect((PartialFunction<Object, ?>) null))
-                .isExactlyInstanceOf(NullPointerException.class)
-                .hasMessage("partialFunction is null");
+    public void shouldIgnoreNullPartialFunctionWhenThereAreNoElementsToCollect() {
+        assertThat(empty().collect((PartialFunction<Object, ?>) null)).isEmpty();
     }
 
     @Test
@@ -809,9 +807,14 @@ public void shouldFoldNil() {
         assertThat(this.<String> empty().fold("", (a, b) -> a + b)).isEqualTo("");
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenFoldNullOperator() {
-        this.<String> empty().fold(null, null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToFold() {
+        assertThat(this.<String> empty().fold("", null)).isEqualTo("");
+    }
+
+    @Test
+    public void shouldIgnoreNullOperatorAndTolerateNullZeroWhenThereAreNoElementsToFold() {
+        assertThat(this.<String> empty().fold(null, null)).isEqualTo(null);
     }
 
     @Test
@@ -831,9 +834,10 @@ public void shouldFoldLeftNil() {
         assertThat(this.<String> empty().foldLeft("", (xs, x) -> xs + x)).isEqualTo("");
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenFoldLeftNullOperator() {
-        this.<String> empty().foldLeft(null, null);
+    @Test
+    public void shouldTolerateNullOperatorInFoldLeftWhenThereIsNoNeedToInvokeIt() {
+        final Object zeroish = new Object();
+        assertThat(this.<String> empty().foldLeft(zeroish, null)).isEqualTo(zeroish);
     }
 
     @Test
@@ -848,9 +852,10 @@ public void shouldFoldRightNil() {
         assertThat(this.<String> empty().foldRight("", (x, xs) -> x + xs)).isEqualTo("");
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenFoldRightNullOperator() {
-        this.<String> empty().foldRight(null, null);
+    @Test
+    public void shouldTolerateNullOperatorInFoldRightWhenThereIsNoNeedToInvokeIt() {
+        final Object zeroish = new Object();
+        assertThat(this.<String> empty().foldRight(zeroish, null)).isEqualTo(zeroish);
     }
 
     @Test
@@ -1275,8 +1280,8 @@ public void shouldCalculateMaxOfFloatPositiveAndNegativeInfinity() {
 
     // -- maxBy(Comparator)
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenMaxByWithNullComparator() {
+    @Test
+    public void shouldTolerateNullComparatorInMaxByWhenThereIsNoNeedToInvokeIt() {
         of(1).maxBy((Comparator<Integer>) null);
     }
 
@@ -1429,8 +1434,8 @@ public void shouldCalculateMinOfFloatPositiveAndNegativeInfinity() {
 
     // -- minBy(Comparator)
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenMinByWithNullComparator() {
+    @Test
+    public void shouldTolerateNullComparatorInMinByWhenThereIsNoNeedToInvokeIt() {
         of(1).minBy((Comparator<Integer>) null);
     }
 
@@ -1528,9 +1533,9 @@ public void shouldCaclNonemptyOrElseSupplier() {
 
     // -- partition
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenPartitionNilAndPredicateIsNull() {
-        empty().partition(null);
+    @Test
+    public void shouldIgnoreNullPredicateWhenThereAreNoElementsToPartition() {
+        assertThat(empty().partition(null)).isEqualTo(Tuple.of(empty(), empty()));
     }
 
     @Test
@@ -1608,13 +1613,13 @@ public void shouldComputeProductOfBigDecimal() {
     // -- reduceOption
 
     @Test
-    public void shouldThrowWhenReduceOptionNil() {
+    public void shouldAnswerNoneOnReduceOptionOverNoElements() {
         assertThat(this.<String> empty().reduceOption((a, b) -> a + b)).isSameAs(Option.none());
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceOptionNullOperator() {
-        this.<String> empty().reduceOption(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduceOption() {
+        assertThat(this.<String> empty().reduceOption(null)).isSameAs(Option.none());
     }
 
     @Test
@@ -1629,9 +1634,20 @@ public void shouldThrowWhenReduceNil() {
         this.<String> empty().reduce((a, b) -> a + b);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceNullOperator() {
-        this.<String> empty().reduce(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduce() {
+        // empty().reduce(f) should fail the same way, whether f is null or not null.
+        try {
+            this.<String>empty().reduce(null);
+            fail("How did empty().reduce() not throw an exception?!");
+        } catch (Exception caughtWithNullOperator) {
+            try {
+                this.<String>empty().reduce((a, b) -> a + b);
+                fail("How did empty().reduce() not throw an exception?!");
+            } catch (Exception caughtWithValidOperator) {
+                assertThat(caughtWithNullOperator.getClass()).isEqualTo(caughtWithValidOperator.getClass());
+            }
+        }
     }
 
     @Test
@@ -1642,13 +1658,13 @@ public void shouldReduceNonNil() {
     // -- reduceLeftOption
 
     @Test
-    public void shouldThrowWhenReduceLeftOptionNil() {
+    public void shouldAnswerNoneOnReduceLeftOptionOverNoElements() {
         assertThat(this.<String> empty().reduceLeftOption((a, b) -> a + b)).isSameAs(Option.none());
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceLeftOptionNullOperator() {
-        this.<String> empty().reduceLeftOption(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduceLeftOption() {
+        assertThat(this.<String> empty().reduceLeftOption(null)).isSameAs(Option.none());
     }
 
     @Test
@@ -1663,9 +1679,20 @@ public void shouldThrowWhenReduceLeftNil() {
         this.<String> empty().reduceLeft((a, b) -> a + b);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceLeftNullOperator() {
-        this.<String> empty().reduceLeft(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduceLeft() {
+        // empty().reduceLeft(f) should fail the same way, whether f is null or not null.
+        try {
+            this.<String>empty().reduceLeft(null);
+            fail("How did empty().reduceLeft() not throw an exception?!");
+        } catch (Exception caughtWithNullOperator) {
+            try {
+                this.<String>empty().reduceLeft((a, b) -> a + b);
+                fail("How did empty().reduceLeft() not throw an exception?!");
+            } catch (Exception caughtWithValidOperator) {
+                assertThat(caughtWithNullOperator.getClass()).isEqualTo(caughtWithValidOperator.getClass());
+            }
+        }
     }
 
     @Test
@@ -1676,13 +1703,13 @@ public void shouldReduceLeftNonNil() {
     // -- reduceRightOption
 
     @Test
-    public void shouldThrowWhenReduceRightOptionNil() {
+    public void shouldAnswerNoneOnReduceRightOptionOverNoElements() {
         assertThat(this.<String> empty().reduceRightOption((a, b) -> a + b)).isSameAs(Option.none());
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceRightOptionNullOperator() {
-        this.<String> empty().reduceRightOption(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduceRightOption() {
+        assertThat(this.<String> empty().reduceRightOption(null)).isSameAs(Option.none());
     }
 
     @Test
@@ -1697,9 +1724,20 @@ public void shouldThrowWhenReduceRightNil() {
         this.<String> empty().reduceRight((a, b) -> a + b);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenReduceRightNullOperator() {
-        this.<String> empty().reduceRight(null);
+    @Test
+    public void shouldIgnoreNullOperatorWhenThereAreNoElementsToReduceRight() {
+        // empty().reduceRight(f) should fail the same way, whether f is null or not null.
+        try {
+            this.<String>empty().reduceRight(null);
+            fail("How did empty().reduceRight() not throw an exception?!");
+        } catch (Exception caughtWithNullOperator) {
+            try {
+                this.<String>empty().reduceRight((a, b) -> a + b);
+                fail("How did empty().reduceRight() not throw an exception?!");
+            } catch (Exception caughtWithValidOperator) {
+                assertThat(caughtWithNullOperator.getClass()).isEqualTo(caughtWithValidOperator.getClass());
+            }
+        }
     }
 
     @Test
@@ -2461,9 +2499,9 @@ public void shouldZipWithNonNilsOfSameSize() {
         assertThat(actual).isEqualTo(expected);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowIfZipWithThatIsNull() {
-        empty().zip(null);
+    @Test
+    public void shouldIgnoreNullIfThereIsNothingToZip() {
+        assertThat(empty().zip(null)).isEmpty();
     }
 
     // -- zipAll
diff --git a/src/test/java/io/vavr/collection/CharSeqTest.java b/src/test/java/io/vavr/collection/CharSeqTest.java
index f8190177e..a69bec890 100644
--- a/src/test/java/io/vavr/collection/CharSeqTest.java
+++ b/src/test/java/io/vavr/collection/CharSeqTest.java
@@ -943,7 +943,12 @@ public void shouldFoldNil() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenFoldNullOperator() {
-        CharSeq.empty().fold(null, null);
+        CharSeq.of('a').fold(null, null);
+    }
+
+    @Test
+    public void shouldIgnoreFoldNullOperatorWhenNotRequired() {
+        assertThat(CharSeq.empty().fold('0', null)).isEqualTo('0');
     }
 
     @Test
@@ -958,8 +963,8 @@ public void shouldFoldLeftNil() {
         assertThat(CharSeq.empty().foldLeft("", (xs, x) -> xs + x)).isEqualTo("");
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowWhenFoldLeftNullOperator() {
+    @Test
+    public void shouldIgnoreNullOperatorWhenEmpty() {
         CharSeq.empty().foldLeft(null, null);
     }
 
@@ -977,7 +982,7 @@ public void shouldFoldRightNil() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenFoldRightNullOperator() {
-        CharSeq.empty().foldRight(null, null);
+        CharSeq.of('a').foldRight(null, null);
     }
 
     @Test
@@ -1224,7 +1229,12 @@ public void shouldMapToCharSeqWhenMapCharsIsUsed() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenPartitionNilAndPredicateIsNull() {
-        CharSeq.empty().partition(null);
+        CharSeq.of('a').partition(null);
+    }
+
+    @Test
+    public void shouldNotThrowWhenPredicateNullNotRequired() {
+        assertThat(CharSeq.empty().partition(null)).isEqualTo(Tuple.of(Array.empty(), Array.empty()));
     }
 
     @Test
@@ -1277,7 +1287,12 @@ public void shouldComputeMaxOfChar() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenMaxByWithNullComparator() {
-        CharSeq.of('1').maxBy((Comparator<Character>) null);
+        CharSeq.of('1', '2').maxBy((Comparator<Character>) null);
+    }
+
+    @Test
+    public void shouldNotThrowWhenMaxByAndNotRequired() {
+        assertThat(CharSeq.of('1').maxBy((Comparator<Character>)null)).isEqualTo(Option.some('1'));
     }
 
     @Test
@@ -1333,7 +1348,12 @@ public void shouldComputeMinOfChar() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenMinByWithNullComparator() {
-        CharSeq.of('1').minBy((Comparator<Character>) null);
+        CharSeq.of('1', '2').minBy((Comparator<Character>) null);
+    }
+
+    @Test
+    public void shouldIgnoreNullComparatorWhenMinByAndOneElement() {
+        assertThat(CharSeq.of('1').minBy((Comparator<Character>) null)).isEqualTo(Option.some('1'));
     }
 
     @Test
@@ -1402,9 +1422,14 @@ public void shouldThrowWhenReduceNil() {
         CharSeq.empty().reduce((a, b) -> a);
     }
 
+    @Test
+    public void shouldNotThrowWhenReduceNullOperatorNotRequired() {
+        assertThat(CharSeq.of('a').reduce(null)).isEqualTo('a');
+    }
+
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenReduceNullOperator() {
-        CharSeq.empty().reduce(null);
+        CharSeq.of('a', 'b').reduce(null);
     }
 
     @Test
@@ -1419,9 +1444,14 @@ public void shouldThrowWhenReduceLeftNil() {
         CharSeq.empty().reduceLeft((a, b) -> a);
     }
 
+    @Test
+    public void shouldNotThrowWhenReduceLeftNullOperatorNotRequired() {
+        CharSeq.of('a').reduceLeft(null);
+    }
+
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenReduceLeftNullOperator() {
-        CharSeq.empty().reduceLeft(null);
+        CharSeq.of('a', 'b').reduceLeft(null);
     }
 
     @Test
@@ -1436,9 +1466,14 @@ public void shouldThrowWhenReduceRightNil() {
         CharSeq.empty().reduceRight((a, b) -> a);
     }
 
+    @Test
+    public void shouldNotThrowWhenReduceRightNullOperatorNotRequired() {
+        assertThat(CharSeq.of('a').reduceRight(null)).isEqualTo('a');
+    }
+
     @Test(expected = NullPointerException.class)
     public void shouldThrowWhenReduceRightNullOperator() {
-        CharSeq.empty().reduceRight(null);
+        CharSeq.of('a', 'b').reduceRight(null);
     }
 
     @Test
diff --git a/src/test/java/io/vavr/collection/HashSetTest.java b/src/test/java/io/vavr/collection/HashSetTest.java
index dd56e7c56..705ef75f2 100644
--- a/src/test/java/io/vavr/collection/HashSetTest.java
+++ b/src/test/java/io/vavr/collection/HashSetTest.java
@@ -252,11 +252,6 @@ public void shouldZipNonNilsOfSameSize() {
         assertThat(actual).isEqualTo(expected);
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowIfZipWithThatIsNull() {
-        empty().zip(null);
-    }
-
     // TODO move to traversable
     // -- zipAll
 
@@ -387,11 +382,6 @@ public void shouldFindLastOfNonNil() {
         assertThat(actual).isIn(List.of(1, 2, 3, 4));
     }
 
-    @Override
-    public void shouldThrowWhenFoldRightNullOperator() {
-        throw new NullPointerException(); // TODO
-    }
-
     @Override
     public void shouldReturnSomeInitWhenCallingInitOptionOnNonNil() {
         // TODO
diff --git a/src/test/java/io/vavr/collection/IntMap.java b/src/test/java/io/vavr/collection/IntMap.java
index be2cb51c5..534244545 100644
--- a/src/test/java/io/vavr/collection/IntMap.java
+++ b/src/test/java/io/vavr/collection/IntMap.java
@@ -99,7 +99,6 @@ public String toString() {
 
     @Override
     public <R> Seq<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
         final PartialFunction<Tuple2<Integer, T>, R> pf = new PartialFunction<Tuple2<Integer, T>, R>() {
             private static final long serialVersionUID = 1L;
             @Override
@@ -168,7 +167,6 @@ public <U> Seq<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> m
 
     @Override
     public <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return original.foldRight(zero, (e, u) -> f.apply(e._2, u));
     }
 
@@ -245,7 +243,6 @@ public IntMap<T> orElse(Supplier<? extends Iterable<? extends T>> supplier) {
 
     @Override
     public Tuple2<IntMap<T>, IntMap<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return original.partition(p -> predicate.test(p._2)).map(IntMap::of, IntMap::of);
     }
 
@@ -393,14 +390,11 @@ public <U> Seq<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> Seq<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> Seq<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return Stream.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -411,7 +405,6 @@ public Seq<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> Seq<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWithIndex(mapper));
     }
 }
diff --git a/src/test/java/io/vavr/collection/IntMultimap.java b/src/test/java/io/vavr/collection/IntMultimap.java
index ec8a017ee..d6cf52bd4 100644
--- a/src/test/java/io/vavr/collection/IntMultimap.java
+++ b/src/test/java/io/vavr/collection/IntMultimap.java
@@ -100,7 +100,6 @@ public String toString() {
 
     @Override
     public <R> Seq<R> collect(PartialFunction<? super T, ? extends R> partialFunction) {
-        Objects.requireNonNull(partialFunction, "partialFunction is null");
         final PartialFunction<Tuple2<Integer, T>, R> pf = new PartialFunction<Tuple2<Integer, T>, R>() {
             private static final long serialVersionUID = 1L;
             @Override
@@ -169,7 +168,6 @@ public <U> Seq<U> flatMap(Function<? super T, ? extends Iterable<? extends U>> m
 
     @Override
     public <U> U foldRight(U zero, BiFunction<? super T, ? super U, ? extends U> f) {
-        Objects.requireNonNull(f, "f is null");
         return original.foldRight(zero, (e, u) -> f.apply(e._2, u));
     }
 
@@ -246,7 +244,6 @@ public IntMultimap<T> orElse(Supplier<? extends Iterable<? extends T>> supplier)
 
     @Override
     public Tuple2<IntMultimap<T>, IntMultimap<T>> partition(Predicate<? super T> predicate) {
-        Objects.requireNonNull(predicate, "predicate is null");
         return original.partition(p -> predicate.test(p._2)).map(IntMultimap::of, IntMultimap::of);
     }
 
@@ -394,14 +391,11 @@ public <U> Seq<Tuple2<T, U>> zip(Iterable<? extends U> that) {
 
     @Override
     public <U, R> Seq<R> zipWith(Iterable<? extends U> that, BiFunction<? super T, ? super U, ? extends R> mapper) {
-        Objects.requireNonNull(that, "that is null");
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWith(that, mapper));
     }
 
     @Override
     public <U> Seq<Tuple2<T, U>> zipAll(Iterable<? extends U> that, T thisElem, U thatElem) {
-        Objects.requireNonNull(that, "that is null");
         return Stream.ofAll(iterator().zipAll(that, thisElem, thatElem));
     }
 
@@ -412,7 +406,6 @@ public Seq<Tuple2<T, Integer>> zipWithIndex() {
 
     @Override
     public <U> Seq<U> zipWithIndex(BiFunction<? super T, ? super Integer, ? extends U> mapper) {
-        Objects.requireNonNull(mapper, "mapper is null");
         return Stream.ofAll(iterator().zipWithIndex(mapper));
     }
 }
diff --git a/src/test/java/io/vavr/collection/JavaConvertersTest.java b/src/test/java/io/vavr/collection/JavaConvertersTest.java
index d7b41d87c..505c977f4 100644
--- a/src/test/java/io/vavr/collection/JavaConvertersTest.java
+++ b/src/test/java/io/vavr/collection/JavaConvertersTest.java
@@ -240,14 +240,13 @@ public void shouldAddElementAtSizeIndexToNonEmpty() {
 
     // -- addAll(Collection)
 
-    @Test(expected = NullPointerException.class)
     public void shouldThrowNPEWhenAddingAllNullCollectionToEmpty() {
-        empty().addAll(null);
+        ifSupported(() -> empty().addAll(null), NullPointerException.class);
     }
 
-    @Test(expected = NullPointerException.class)
+    @Test
     public void shouldThrowNPEWhenAddingAllNullCollectionToNonEmpty() {
-        of('1').addAll(null);
+        ifSupported(() -> of('1').addAll(null), NullPointerException.class);
     }
 
     @Test
@@ -292,14 +291,12 @@ public void shouldReturnTrueIfAddAllNonEmptyToNonEmpty() {
 
     @Test
     public void shouldThrowNPEWhenAddingAllNullCollectionAtFirstIndexToEmpty() {
-        assertThatThrownBy(() -> empty().addAll(0, null))
-                .isInstanceOf(NullPointerException.class);
+        ifSupported(() -> empty().addAll(0, null), NullPointerException.class);
     }
 
     @Test
     public void shouldThrowNPEWhenAddingAllNullCollectionAtFirstIndexToNonEmpty() {
-        assertThatThrownBy(() -> of('1').addAll(0, null))
-                .isInstanceOf(NullPointerException.class);
+        ifSupported(() -> of('1').addAll(0, null), NullPointerException.class);
     }
 
     @Test
@@ -1851,15 +1848,13 @@ public void shouldRemoveNull() {
     // -- removeAll(Collection)
 
     @Test
-    public void shouldThrowNPEWhenCallingRemoveAllNullWhenEmpty() {
-        assertThatThrownBy(() -> empty().removeAll(null))
-                .isInstanceOf(NullPointerException.class);
+    public void shouldNotThrowWhenCallingRemoveAllNullAndEmpty() {
+        ifSupported(() -> empty().removeAll(null));
     }
 
     @Test
     public void shouldThrowNPEWhenCallingRemoveAllNullWhenNotEmpty() {
-        assertThatThrownBy(() -> of('1').removeAll(null))
-                .isInstanceOf(NullPointerException.class);
+        ifSupported(() -> of('1').removeAll(null), NullPointerException.class);
     }
 
     @Test
@@ -1945,23 +1940,25 @@ public void shouldReplaceAllOfNonEmpty() {
     // -- retainAll(Collection)
 
     @Test
-    public void shouldThrowNPEWhenCallingRetainAllNullWhenEmpty() {
-        assertThatThrownBy(() -> empty().retainAll(null))
-                .isInstanceOf(NullPointerException.class);
+    public void shouldIgnoreCollectionWhenCallingRetainAllNullWhenEmpty() {
+        ifSupported(() -> empty().retainAll(null));
     }
 
     @Test
     public void shouldThrowNPEWhenCallingRetainAllNullWhenNotEmpty() {
-        assertThatThrownBy(() -> of('1').retainAll(null))
-                .isInstanceOf(NullPointerException.class);
+        ifSupported(() -> of('1').retainAll(null), NullPointerException.class);
     }
 
     // -- retainAll(Collection) tests
 
     @Test
-    public void shouldThrowWhenRetainAllNull() {
-        assertThatThrownBy(() -> empty().retainAll(null)).isInstanceOf(NullPointerException.class);
-        assertThatThrownBy(() -> of('1').retainAll(null)).isInstanceOf(NullPointerException.class);
+    public void shouldIgnoreCollectionWhenRetainAllNullAndEmpty() {
+        ifSupported(() -> empty().retainAll(null));
+    }
+
+    @Test
+    public void shouldThrowWhenNotEmptyAndRetainAllNull() {
+        ifSupported(() -> of('1').retainAll(null), NullPointerException.class);
     }
 
     @Test
@@ -2279,9 +2276,8 @@ private final void ifSupported(Runnable test, Class<? extends Throwable>... expe
         } catch (Throwable x) {
             if (changePolicy == IMMUTABLE) {
                 if (!(x instanceof UnsupportedOperationException)) {
-                    final boolean isJavaCollection = empty().getClass().getName().startsWith("java.util.");
                     // DEV-NOTE: Java's collections throw UnsupportedOperationException inconsistently
-                    if (!isJavaCollection) {
+                    if (!isJavaCollection()) {
                         Assert.fail("Operation should throw " + UnsupportedOperationException.class.getName() + " but found " + x.getClass().getName() + ":\n" + x.getMessage());
                     }
                 }
@@ -2292,11 +2288,19 @@ private final void ifSupported(Runnable test, Class<? extends Throwable>... expe
                         return;
                     }
                 }
+                if (isJavaCollection() && expectedExceptionTypes.length == 0 && actualType.equals(NullPointerException.class)) {
+                    // DEV-NOTE: specifically for TestCase 7 java.util.ArrayList. Do we need to test java collections at all?
+                    return;
+                }
                 throw x;
             }
         }
     }
 
+    private boolean isJavaCollection() {
+        return empty().getClass().getName().startsWith("java.util.");
+    }
+
     static final class ListFactory {
 
         private final Function<Object[], java.util.List<Object>> listFactory;
diff --git a/src/test/java/io/vavr/concurrent/FutureTest.java b/src/test/java/io/vavr/concurrent/FutureTest.java
index f60f45586..10df2a6d7 100644
--- a/src/test/java/io/vavr/concurrent/FutureTest.java
+++ b/src/test/java/io/vavr/concurrent/FutureTest.java
@@ -404,7 +404,7 @@ public void shouldCreateAndCompleteAFutureUsingTrivialExecutorServiceAndCallable
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowNPEWhenExecutorIsNullUsingCallable() {
-        Future.ofCallable(null, () -> 1);
+        Future.ofCallable(null, () -> 1).await();
     }
 
     @Test(expected = NullPointerException.class)
@@ -781,7 +781,7 @@ public void shouldCollectEmptyFutureUsingPartialFunction() {
     @Test(expected = NullPointerException.class)
     public void shouldThrowExceptionOnNullCollectPartialFunction() {
         final PartialFunction<Integer, String> pf = null;
-        Future.of(zZz(3)).collect(pf);
+        Future.of(zZz(3)).collect(pf).get();
     }
 
     // -- executorService()
diff --git a/src/test/java/io/vavr/control/EitherTest.java b/src/test/java/io/vavr/control/EitherTest.java
index b120ccb68..89c2a88b1 100644
--- a/src/test/java/io/vavr/control/EitherTest.java
+++ b/src/test/java/io/vavr/control/EitherTest.java
@@ -116,11 +116,9 @@ public void shouldFoldRight() {
 
     // -- sequence
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenSequencingNull() {
-        assertThatThrownBy(() -> Either.sequence(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("eithers is null");
+        Either.sequence(null);
     }
 
     @Test
@@ -157,11 +155,9 @@ public void shouldSequenceNonEmptyIterableOfMixedEither() {
 
     // -- sequenceRight
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenSequencingRightNull() {
-        assertThatThrownBy(() -> Either.sequenceRight(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("eithers is null");
+        Either.sequenceRight(null);
     }
 
     @Test
@@ -217,11 +213,9 @@ public void shouldHandleTransformOnLeft() {
 
     // -- traverse
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenTraversingNull() {
-        assertThatThrownBy(() -> Either.traverse(null, null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("values is null");
+        Either.traverse(null, null);
     }
 
     @Test
@@ -259,11 +253,9 @@ public void shouldTraverseNonEmptyIterableOfMixedEither() {
 
     // -- traverseRight
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenTraversingRightNull() {
-        assertThatThrownBy(() -> Either.traverseRight(null, null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("values is null");
+        Either.traverseRight(null, null);
     }
 
     @Test
@@ -434,11 +426,9 @@ public void shouldFilterNotLeft() {
         assertThat(either.filterNot(i -> true).get()).isSameAs(either);
     }
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenNullPredicate() {
-        assertThatThrownBy(() -> Either.left(42).filterNot(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("predicate is null");
+        Either.left(42).filterNot(null);
     }
 
     // -- filterOrElse
diff --git a/src/test/java/io/vavr/control/OptionTest.java b/src/test/java/io/vavr/control/OptionTest.java
index 20e08f4c5..26df2e12e 100644
--- a/src/test/java/io/vavr/control/OptionTest.java
+++ b/src/test/java/io/vavr/control/OptionTest.java
@@ -119,8 +119,8 @@ public void shouldNotExecuteIfFalse() {
         })).isEqualTo(Option.none());
     }
 
-    @Test(expected = NullPointerException.class)
-    public void shouldThrowExceptionOnWhenWithProvider() {
+    @Test
+    public void shouldIgnoreSupplierNullOnWhenWithProvider() {
         assertThat(Option.when(false, (Supplier<?>) null)).isEqualTo(Option.none());
     }
 
@@ -316,15 +316,10 @@ public void shouldBePresentOnIsEmptyWhenValue() {
 
     // -- onEmpty
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowNullPointerExceptionWhenNullOnEmptyActionPassed() {
-        try {
-            final Option<String> none = Option.none();
-            none.onEmpty(null);
-            Assert.fail("No exception was thrown");
-        } catch (NullPointerException exc) {
-            assertThat(exc.getMessage()).isEqualTo("action is null");
-        }
+        final Option<String> none = Option.none();
+        none.onEmpty(null);
     }
 
     @Test
@@ -381,11 +376,9 @@ public void shouldReturnNoneOnFilterNotWhenValueIsNotDefinedAndPredicateNotMatch
         assertThat(Option.<Integer>none().filterNot(i -> i == 1)).isEqualTo(Option.none());
     }
 
-    @Test
+    @Test(expected = NullPointerException.class)
     public void shouldThrowWhenFilterNotPredicateIsNull() {
-        assertThatThrownBy(() -> Option.of(1).filterNot(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("predicate is null");
+        Option.of(1).filterNot(null);
     }
 
     // -- map
diff --git a/src/test/java/io/vavr/control/TryTest.java b/src/test/java/io/vavr/control/TryTest.java
index f01719841..9f653615e 100644
--- a/src/test/java/io/vavr/control/TryTest.java
+++ b/src/test/java/io/vavr/control/TryTest.java
@@ -261,8 +261,8 @@ public void shouldCreateFailureWhenCallingTryOfCheckedFunction0() {
     }
 
     @Test
-    public void shouldThrowNullPointerExceptionWhenCallingTryOfCheckedFunction0() {
-        assertThatThrownBy(() -> Try.of(null)).isInstanceOf(NullPointerException.class).hasMessage("supplier is null");
+    public void shouldReturnFailureWithNPEWhenCallingTryOfCheckedFunction0Null() {
+        assertThat(Try.of(null).getCause()).isInstanceOf(NullPointerException.class);
     }
 
     // -- Try.fold
@@ -292,7 +292,7 @@ public void shouldCreateSuccessWhenCallingTryOfSupplier() {
 
     @Test
     public void shouldThrowNullPointerExceptionWhenCallingTryOfSupplier() {
-        assertThatThrownBy(() -> Try.ofSupplier(null)).isInstanceOf(NullPointerException.class).hasMessage("supplier is null");
+        assertThatThrownBy(() -> Try.ofSupplier(null)).isInstanceOf(NullPointerException.class);
     }
 
     @Test
@@ -318,7 +318,7 @@ public void shouldCreateFailureWhenCallingTryOfCallable() {
 
     @Test
     public void shouldThrowNullPointerExceptionWhenCallingTryOfCallable() {
-        assertThatThrownBy(() -> Try.ofCallable(null)).isInstanceOf(NullPointerException.class).hasMessage("callable is null");
+        assertThatThrownBy(() -> Try.ofCallable(null)).isInstanceOf(NullPointerException.class);
     }
 
     // -- Try.run
@@ -338,7 +338,7 @@ public void shouldCreateFailureWhenCallingTryRunCheckedRunnable() {
 
     @Test
     public void shouldThrowNullPointerExceptionWhenCallingTryRunCheckedRunnable() {
-        assertThatThrownBy(() -> Try.run(null)).isInstanceOf(NullPointerException.class).hasMessage("runnable is null");
+        assertThat(Try.run(null).getCause()).isInstanceOf(NullPointerException.class);
     }
 
     // -- Try.runRunnable
@@ -358,7 +358,7 @@ public void shouldCreateFailureWhenCallingTryRunRunnable() {
 
     @Test
     public void shouldThrowNullPointerExceptionWhenCallingTryRunRunnable() {
-        assertThatThrownBy(() -> Try.runRunnable(null)).isInstanceOf(NullPointerException.class).hasMessage("runnable is null");
+        assertThatThrownBy(() -> Try.runRunnable(null)).isInstanceOf(NullPointerException.class);
     }
 
     // -- Try.withResources
@@ -1089,8 +1089,7 @@ public void shouldFilterNotWithExceptionOnFailure() {
     @Test
     public void failureShouldThrowWhenFilterNotWithNullPredicate() {
         assertThatThrownBy(() -> failure().filterNot(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("predicate is null");
+                .isInstanceOf(NullPointerException.class);
     }
 
     // -- flatMap
@@ -1500,8 +1499,7 @@ public void shouldFilterNotWithExceptionOnSuccess() {
     @Test
     public void successShouldThrowWhenFilterNotWithNullPredicate() {
         assertThatThrownBy(() -> success().filterNot(null))
-                .isInstanceOf(NullPointerException.class)
-                .hasMessage("predicate is null");
+                .isInstanceOf(NullPointerException.class);
     }
 
     // -- flatMap
diff --git a/src/test/java/io/vavr/control/ValidationTest.java b/src/test/java/io/vavr/control/ValidationTest.java
index 9ecb96786..efefa0d58 100644
--- a/src/test/java/io/vavr/control/ValidationTest.java
+++ b/src/test/java/io/vavr/control/ValidationTest.java
@@ -377,7 +377,12 @@ public void shouldThrowWhenGetOrElseThrowWithFunctionOnInvalid() {
 
     @Test(expected = NullPointerException.class)
     public void shouldThrowNullPointerExceptionWhenGetOrElseThrowNullWithFunctionOnValid() {
-      Validation.<String, Integer> valid(1).getOrElseThrow((Function<? super String, RuntimeException>) null);
+      Validation.<String, Integer> invalid("some error").getOrElseThrow((Function<? super String, RuntimeException>) null);
+    }
+
+    @Test
+    public void shouldIgnoreExceptionSupplierWhenGetOrElseAndNotRequired() {
+        Validation.<String, Integer> valid(1).getOrElseThrow((Function<? super String, RuntimeException>) null);
     }
 
     @Test(expected = NullPointerException.class)