diff --git a/synapse/storage/schema/delta/36/readd_public_rooms.sql b/synapse/storage/schema/delta/36/readd_public_rooms.sql
index 5460a350b6..90d8fd18f9 100644
--- a/synapse/storage/schema/delta/36/readd_public_rooms.sql
+++ b/synapse/storage/schema/delta/36/readd_public_rooms.sql
@@ -16,7 +16,7 @@
 -- Re-add some entries to stream_ordering_to_exterm that were incorrectly deleted
 INSERT INTO stream_ordering_to_exterm (stream_ordering, room_id, event_id)
     SELECT
-        (SELECT max(stream_ordering) FROM events where room_id = e.room_id) AS stream_ordering,
+        (SELECT stream_ordering FROM events where event_id = e.event_id) AS stream_ordering,
         room_id,
         event_id
     FROM event_forward_extremities AS e