diff --git a/ModelDescriber/ObjectModelDescriber.php b/ModelDescriber/ObjectModelDescriber.php
index db373cc..f361151 100644
--- a/ModelDescriber/ObjectModelDescriber.php
+++ b/ModelDescriber/ObjectModelDescriber.php
@@ -55,9 +55,9 @@ class ObjectModelDescriber implements ModelDescriberInterface, ModelRegistryAwar
         $properties = $schema->getProperties();
 
         $class = $model->getType()->getClassName();
-        $context = [];
+        $context = ['serializer_groups' => null]; // Use the SerializerExtractor with no groups check (sf >= 5.1)
         if (null !== $model->getGroups()) {
-            $context = ['serializer_groups' => array_filter($model->getGroups(), 'is_string')];
+            $context['serializer_groups'] = array_filter($model->getGroups(), 'is_string');
         }
 
         $annotationsReader = new AnnotationsReader($this->doctrineReader, $this->modelRegistry);