1 files changed, 1 insertions, 1 deletions
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index fb4823a5cc..0b805af60c 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -475,7 +475,7 @@ class RoomCreationHandler(BaseHandler):
             ):
                 await self.room_member_handler.update_membership(
                     requester,
-                    UserID.from_string(old_event["state_key"]),
+                    UserID.from_string(old_event.state_key),
                     new_room_id,
                     "ban",
                     ratelimit=False,