2 files changed, 1 insertions, 1 deletions
diff --git a/changelog.d/15733.misc b/changelog.d/15733.misc
new file mode 100644
index 0000000000..3ae7be3c27
--- /dev/null
+++ b/changelog.d/15733.misc
@@ -0,0 +1 @@
+Remove superfluous `room_memberships` join from background update.
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index 1b8ec67f54..582875c91a 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -1460,7 +1460,6 @@ class RoomMemberBackgroundUpdateStore(SQLBaseStore):
                 SELECT stream_ordering, event_id, events.room_id, event_json.json
                 FROM events
                 INNER JOIN event_json USING (event_id)
-                INNER JOIN room_memberships USING (event_id)
                 WHERE ? <= stream_ordering AND stream_ordering < ?
                 AND type = 'm.room.member'
                 ORDER BY stream_ordering DESC