diff --git a/synapse/storage/databases/main/events_worker.py b/synapse/storage/databases/main/events_worker.py
index 05a05c3cbe..7ddc279508 100644
--- a/synapse/storage/databases/main/events_worker.py
+++ b/synapse/storage/databases/main/events_worker.py
@@ -822,7 +822,7 @@ class EventsWorkerStore(SQLBaseStore):
                   rej.reason
                 FROM events AS e
                   JOIN event_json AS ej USING (event_id)
-                  LEFT JOIN rooms r USING (room_id)
+                  LEFT JOIN rooms r ON r.room_id = e.room_id
                   LEFT JOIN rejections as rej USING (event_id)
                 WHERE """