diff --git a/test/ContainerTest.php b/test/ContainerTest.php
index 214cf8e..ce5a6a1 100644
--- a/test/ContainerTest.php
+++ b/test/ContainerTest.php
@@ -342,6 +342,7 @@ public function testDetailedRecursiveIteration()
         $iterator = new TestAsset\RecursiveIteratorIterator($nav, \RecursiveIteratorIterator::SELF_FIRST);
         $iterator->logger = array();
         $iterator->rewind();
+        //#4517 logging with walking through RecursiveIterator
         while ($iterator->valid()) {
             $iterator->current();
             $iterator->next();
diff --git a/test/TestAsset/RecursiveIteratorIterator.php b/test/TestAsset/RecursiveIteratorIterator.php
index 863bcc8..4265f36 100644
--- a/test/TestAsset/RecursiveIteratorIterator.php
+++ b/test/TestAsset/RecursiveIteratorIterator.php
@@ -15,7 +15,7 @@ class RecursiveIteratorIterator extends \RecursiveIteratorIterator
      *
      * @var \ArrayAccess|array
      */
-    public $logger;
+    public $logger = array();
 
     public function beginIteration()
     {