diff --git a/headers/binary_set.h b/headers/binary_set.h
index 1910b93..fef4c80 100644
--- a/headers/binary_set.h
+++ b/headers/binary_set.h
@@ -165,11 +165,16 @@ static inline void destroy_binary_set(binary_set_s * set, const destroy_binary_s
 }
 
 static inline bool contains_binary_set(const binary_set_s set, const BINARY_SET_DATA_TYPE element) {
+    if (set.compare) { // uses buildin binary search implmentation if compare function is specified
+        return bsearch(&element, set.elements, set.size, sizeof(BINARY_SET_DATA_TYPE), set.compare) != NULL;
+    }
+    // else custom binary search is used as memcmp takes three arguments as input
+    // (bsearch requires a 2 argument compare function). IF ONLY NESTED FUNCTION WERE PART OF THE C STANDARD.
+
     BINARY_SET_DATA_TYPE * base = set.elements;
     for (size_t limit = set.size; limit != 0; limit >>= 1) {
         BINARY_SET_DATA_TYPE * current_element = base + (limit >> 1);
-        printf("%d ", current_element->sub_one);
-        const int cmp = set.compare ? set.compare(&element, current_element) : memcmp(&element, current_element, sizeof(BINARY_SET_DATA_TYPE));
+        const int cmp = memcmp(&element, current_element, sizeof(BINARY_SET_DATA_TYPE));
         if (cmp == 0) {
             return true;
         }
@@ -178,7 +183,6 @@ static inline bool contains_binary_set(const binary_set_s set, const BINARY_SET_
             limit--;
         }
     }
-    puts("\n");
 
     return false;
 }
diff --git a/test/binary_set/infinite_realloc_binary_set.c b/test/binary_set/infinite_realloc_binary_set.c
index 6a5afae..2d3442a 100644
--- a/test/binary_set/infinite_realloc_binary_set.c
+++ b/test/binary_set/infinite_realloc_binary_set.c
@@ -32,7 +32,9 @@ TEST IRBS_02(void) {
 
     binary_set_s united = union_binary_set(set_one, set_two, NULL);
     for (int i = 0; i < (REALLOC_BINARY_SET_CHUNK - 1) * 3; ++i) {
-        ASSERTm("[IRBS-ERROR] expected set to contain i", contains_binary_set(united, (BINARY_SET_DATA_TYPE) { .sub_one = i, }));
+        BINARY_SET_DATA_TYPE element = { 0 };
+        element.sub_one = i;
+        ASSERTm("[IRBS-ERROR] expected set to contain i", contains_binary_set(united, element));
     }
 
     destroy_binary_set(&united, NULL);