diff --git a/src/ClassDiagramRenderer/ClassDiagram.php b/src/ClassDiagramRenderer/ClassDiagram.php
index f2ab4a7..eba0979 100644
--- a/src/ClassDiagramRenderer/ClassDiagram.php
+++ b/src/ClassDiagramRenderer/ClassDiagram.php
@@ -22,8 +22,6 @@ public function addNode(Node $node): self
     {
         $this->nodes[] = $node;
 
-        Node::sortNodes($this->nodes);
-
         return $this;
     }
 
@@ -31,13 +29,14 @@ public function addRelationships(Relationship ...$relationships): self
     {
         $this->relationships = [...$this->relationships, ...$relationships];
 
-        Relationship::sortRelationships($this->relationships);
-
         return $this;
     }
 
     public function render(): string
     {
+        Node::sortNodes($this->nodes);
+        Relationship::sortRelationships($this->relationships);
+
         $output = "classDiagram\n";
 
         foreach ($this->nodes as $node) {
diff --git a/src/ClassDiagramRenderer/Node/Node.php b/src/ClassDiagramRenderer/Node/Node.php
index d1d669f..38ecd38 100644
--- a/src/ClassDiagramRenderer/Node/Node.php
+++ b/src/ClassDiagramRenderer/Node/Node.php
@@ -10,37 +10,32 @@
 
 abstract class Node
 {
-    /** @var Node[] */
-    protected array $extends = [];
-
-    /** @var Node[] */
-    protected array $implements = [];
-
-    /** @var Node[] */
-    protected array $properties = [];
+    protected Nodes $extends;
+    protected Nodes $implements;
+    protected Nodes $properties;
 
     public function __construct(protected string $name)
     {
+        $this->extends = Nodes::empty();
+        $this->implements = Nodes::empty();
+        $this->properties = Nodes::empty();
     }
 
     abstract public function render(): string;
 
     public function extends(Node $node): void
     {
-        $this->extends[] = $node;
-        self::sortNodes($this->extends);
+        $this->extends->add($node);
     }
 
     public function implements(Node $node): void
     {
-        $this->implements[] = $node;
-        self::sortNodes($this->implements);
+        $this->implements->add($node);
     }
 
     public function composition(Node $node): void
     {
-        $this->properties[] = $node;
-        self::sortNodes($this->properties);
+        $this->properties->add($node);
     }
 
     public function nodeName(): string
@@ -54,9 +49,9 @@ public function nodeName(): string
     public function relationships(): array
     {
         return [
-            ...array_map(fn(Node $extendsNode)    => new Inheritance($this, $extendsNode), $this->extends),
-            ...array_map(fn(Node $implementsNode) => new Realization($this, $implementsNode), $this->implements),
-            ...array_map(fn(Node $propertyNode) => new Composition($this, $propertyNode), $this->properties),
+            ...array_map(fn(Node $extendsNode)    => new Inheritance($this, $extendsNode), $this->extends->getAllNodes()),
+            ...array_map(fn(Node $implementsNode) => new Realization($this, $implementsNode), $this->implements->getAllNodes()),
+            ...array_map(fn(Node $propertyNode) => new Composition($this, $propertyNode), $this->properties->getAllNodes()),
         ];
     }
 
diff --git a/src/ClassDiagramRenderer/Node/Nodes.php b/src/ClassDiagramRenderer/Node/Nodes.php
index 44717df..ec15871 100644
--- a/src/ClassDiagramRenderer/Node/Nodes.php
+++ b/src/ClassDiagramRenderer/Node/Nodes.php
@@ -15,6 +15,11 @@ public function __construct()
         $this->nodes = [];
     }
 
+    public static function empty(): self
+    {
+        return new self();
+    }
+
     public function add(Node $node): self
     {
         $this->nodes[$node->nodeName()] = $node;