1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/events/builder.py b/synapse/events/builder.py
index df4f950fec..07df258e6e 100644
--- a/synapse/events/builder.py
+++ b/synapse/events/builder.py
@@ -98,7 +98,7 @@ class EventBuilder:
         return self._state_key is not None
 
     async def build(
-        self, prev_event_ids: List[str], auth_event_ids: Optional[List[str]]
+        self, prev_event_ids: List[str], auth_event_ids: Optional[List[str]],
     ) -> EventBase:
         """Transform into a fully signed and hashed event