diff --git a/DependencyInjection/FOSElasticaExtension.php b/DependencyInjection/FOSElasticaExtension.php
index 292a9a5..89ac3dd 100644
--- a/DependencyInjection/FOSElasticaExtension.php
+++ b/DependencyInjection/FOSElasticaExtension.php
@@ -391,7 +391,13 @@ class FOSElasticaExtension extends Extension
             $arguments[] = array(new Reference($callbackId), 'serialize');
         } else {
             $abstractId = 'fos_elastica.object_persister';
-            $arguments[] = $this->indexConfigs[$indexName]['types'][$typeName]['mapping']['properties'];
+            $mapping = $this->indexConfigs[$indexName]['types'][$typeName]['mapping'];
+            $argument = $mapping['properties'];
+            if(isset($mapping['_parent'])){
+                $argument['_parent'] = $mapping['_parent'];
+            }
+            $arguments[] = $argument;
+
         }
 
         $serviceId = sprintf('fos_elastica.object_persister.%s.%s', $indexName, $typeName);