diff --git a/synapse/storage/events.py b/synapse/storage/events.py
index d2feee8db..ad026b5e0 100644
--- a/synapse/storage/events.py
+++ b/synapse/storage/events.py
@@ -600,7 +600,8 @@ class EventsStore(SQLBaseStore):
                 "rejections",
                 "redactions",
                 "room_memberships",
-                "state_events"
+                "state_events",
+                "topics"
             ):
                 txn.executemany(
                     "DELETE FROM %s WHERE event_id = ?" % (table,),