1 files changed, 3 insertions, 1 deletions
diff --git a/synapse/rest/client/sync.py b/synapse/rest/client/sync.py
index 53c385a86c..0bf32f873b 100644
--- a/synapse/rest/client/sync.py
+++ b/synapse/rest/client/sync.py
@@ -99,6 +99,7 @@ class SyncRestServlet(RestServlet):
         self.presence_handler = hs.get_presence_handler()
         self._server_notices_sender = hs.get_server_notices_sender()
         self._event_serializer = hs.get_event_client_serializer()
+        self._msc2654_enabled = hs.config.experimental.msc2654_enabled
 
     async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         # This will always be set by the time Twisted calls us.
@@ -521,7 +522,8 @@ class SyncRestServlet(RestServlet):
             result["ephemeral"] = {"events": ephemeral_events}
             result["unread_notifications"] = room.unread_notifications
             result["summary"] = room.summary
-            result["org.matrix.msc2654.unread_count"] = room.unread_count
+            if self._msc2654_enabled:
+                result["org.matrix.msc2654.unread_count"] = room.unread_count
 
         return result