diff --git a/src/collective/elasticsearch/manager.py b/src/collective/elasticsearch/manager.py
index 06c402f..5a32eba 100644
--- a/src/collective/elasticsearch/manager.py
+++ b/src/collective/elasticsearch/manager.py
@@ -29,7 +29,6 @@
 
 # Custom serializer to handle cases where set() data is passed to an index
 class PloneJSONSerializer(JSONSerializer):
-
     def default(self, data):
         if isinstance(data, set):
             return [i for i in data]