diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 62bce139d..0eb7c8fd8 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -2356,6 +2356,7 @@ class UnitOfWork implements PropertyChangedListener
             $this->collectionUpdates =
             $this->extraUpdates =
             $this->readOnlyObjects =
+            $this->visitedCollections =
             $this->orphanRemovals = array();
 
             if ($this->commitOrderCalculator !== null) {