diff --git a/lib/Gedmo/Loggable/Entity/Repository/LogEntryRepository.php b/lib/Gedmo/Loggable/Entity/Repository/LogEntryRepository.php
index 5b18855779..8bb52cd932 100644
--- a/lib/Gedmo/Loggable/Entity/Repository/LogEntryRepository.php
+++ b/lib/Gedmo/Loggable/Entity/Repository/LogEntryRepository.php
@@ -54,7 +54,7 @@ public function getLogEntriesQuery($entity)
         $dql .= " AND log.objectClass = :objectClass";
         $dql .= " ORDER BY log.version DESC";
 
-        $objectId = $wrapped->getIdentifier();
+        $objectId = (string) $wrapped->getIdentifier();
         $q = $this->_em->createQuery($dql);
         $q->setParameters(compact('objectId', 'objectClass'));
 
@@ -86,7 +86,7 @@ public function revert($entity, $version = 1)
         $dql .= " AND log.version <= :version";
         $dql .= " ORDER BY log.version ASC";
 
-        $objectId = $wrapped->getIdentifier();
+        $objectId = (string) $wrapped->getIdentifier();
         $q = $this->_em->createQuery($dql);
         $q->setParameters(compact('objectId', 'objectClass', 'version'));
         $logs = $q->getResult();