diff --git a/lib/PhpParser/NodeTraverser.php b/lib/PhpParser/NodeTraverser.php
index fe3045a..f9ef079 100644
--- a/lib/PhpParser/NodeTraverser.php
+++ b/lib/PhpParser/NodeTraverser.php
@@ -31,16 +31,13 @@ class NodeTraverser implements NodeTraverserInterface
     const REMOVE_NODE = 3;
 
     /** @var NodeVisitor[] Visitors */
-    protected $visitors;
+    protected $visitors = [];
 
     /** @var bool Whether traversal should be stopped */
     protected $stopTraversal;
 
-    /**
-     * Constructs a node traverser.
-     */
     public function __construct() {
-        $this->visitors = [];
+        // for BC
     }
 
     /**