diff --git a/src/HTML5.php b/src/HTML5.php
index 94faa1e0..c857145f 100644
--- a/src/HTML5.php
+++ b/src/HTML5.php
@@ -212,7 +212,10 @@ public function save($dom, $file, $options = array())
         $trav = new Traverser($dom, $stream, $rules, $options);
 
         $trav->walk();
-
+        /*
+         * release the traverser to avoid cyclic references and allow PHP to free memory without waiting for gc_collect_cycles
+         */
+        $rules->unsetTraverser();
         if ($close) {
             fclose($stream);
         }
diff --git a/src/HTML5/Serializer/OutputRules.php b/src/HTML5/Serializer/OutputRules.php
index 1c4e8929..ec467f22 100644
--- a/src/HTML5/Serializer/OutputRules.php
+++ b/src/HTML5/Serializer/OutputRules.php
@@ -182,6 +182,13 @@ public function setTraverser(Traverser $traverser)
         return $this;
     }
 
+    public function unsetTraverser()
+    {
+        $this->traverser = null;
+
+        return $this;
+    }
+
     public function document($dom)
     {
         $this->doctype();