diff --git a/src/IntervalTree.php b/src/IntervalTree.php
index a5b9fa8..43d6d0b 100644
--- a/src/IntervalTree.php
+++ b/src/IntervalTree.php
@@ -139,7 +139,12 @@ public function insert(array $key, $value = null)
             $value = $key;
         }
 
-        $insertNode = new Node($key, $value, $this->nilNode, $this->nilNode, null, Node::COLOR_RED);
+        $insertNode = new Node($key, $value);
+        $insertNode->left = $this->nilNode;
+        $insertNode->right = $this->nilNode;
+        $insertNode->parent = null;
+        $insertNode->color = Node::COLOR_RED;
+        
         $this->treeInsert($insertNode);
         $this->recalcMax($insertNode);
         return $insertNode;
diff --git a/src/Node.php b/src/Node.php
index 041cca7..e2fbafa 100644
--- a/src/Node.php
+++ b/src/Node.php
@@ -45,13 +45,8 @@ class Node
 
     public $max;
 
-    public function __construct($key = null, $value = null, $left = null, $right = null, $parent = null, $color = self::COLOR_BLACK)
+    public function __construct($key = null, $value = null)
     {
-        $this->left = $left;
-        $this->right = $right;
-        $this->parent = $parent;
-        $this->color = $color;
-
         if (is_null($key)) {
             $this->item = new Item($key, $value); // key is supposed to be instance of Interval
         } elseif ($key && is_array($key) && count($key) === 2) {