diff --git a/synapse/replication/slave/storage/events.py b/synapse/replication/slave/storage/events.py
index 6cd3a843d..3f33d473c 100644
--- a/synapse/replication/slave/storage/events.py
+++ b/synapse/replication/slave/storage/events.py
@@ -154,7 +154,6 @@ class SlavedEventStore(BaseSlavedStore):
         DataStore.get_room_events_stream_for_rooms.__func__
     )
     is_host_joined = DataStore.is_host_joined.__func__
-    _is_host_joined = RoomMemberStore.__dict__["_is_host_joined"]
     get_stream_token_for_event = DataStore.get_stream_token_for_event.__func__
 
     _set_before_and_after = staticmethod(DataStore._set_before_and_after)