diff --git a/lib/Doctrine/ORM/EntityManager.php b/lib/Doctrine/ORM/EntityManager.php
index 685fc0d71d7..eadb1f14779 100644
--- a/lib/Doctrine/ORM/EntityManager.php
+++ b/lib/Doctrine/ORM/EntityManager.php
@@ -348,9 +348,14 @@ public function createQueryBuilder()
      *
      * @throws \Doctrine\ORM\OptimisticLockException If a version check on an entity that
      *         makes use of optimistic locking fails.
+     *
+     * @throws Exception
      */
     public function flush($entity = null)
     {
+        if (!is_null($entity))
+            throw new Exception('You shall not use single entity flush!');
+
         $this->errorIfClosed();
 
         $this->unitOfWork->commit($entity);