diff --git a/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php b/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
index 3e6578b9c26..911b4138701 100644
--- a/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
+++ b/lib/Doctrine/ORM/Persisters/Entity/BasicEntityPersister.php
@@ -183,7 +183,7 @@ class BasicEntityPersister implements EntityPersister
      *
      * @var IdentifierFlattener
      */
-    final protected $identifierFlattener;
+    protected $identifierFlattener;
 
     /** @var CachedPersisterContext */
     protected $currentPersisterContext;