diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 59ee1c1cb..1336a57f3 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -1582,17 +1582,13 @@ class UnitOfWork implements PropertyChangedListener
     {
         $oid = spl_object_hash($entity);
 
-        if ( ! isset($this->entityIdentifiers[$oid])) {
+        if (empty($this->entityIdentifiers[$oid])) {
             return false;
         }
 
         $classMetadata = $this->em->getClassMetadata(get_class($entity));
         $idHash        = implode(' ', $this->entityIdentifiers[$oid]);
 
-        if ($idHash === '') {
-            return false;
-        }
-
         return isset($this->identityMap[$classMetadata->rootEntityName][$idHash]);
     }