1 files changed, 1 insertions, 0 deletions
diff --git a/synapse/rest/client/sync.py b/synapse/rest/client/sync.py
index 2a22bc14ec..13aed1dc85 100644
--- a/synapse/rest/client/sync.py
+++ b/synapse/rest/client/sync.py
@@ -982,6 +982,7 @@ class SlidingSyncRestServlet(RestServlet):
         serialized_rooms: Dict[str, JsonDict] = {}
         for room_id, room_result in rooms.items():
             serialized_rooms[room_id] = {
+                "bump_stamp": room_result.bump_stamp,
                 "joined_count": room_result.joined_count,
                 "invited_count": room_result.invited_count,
                 "notification_count": room_result.notification_count,