diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index ff4e85d2e9..88bb7ab52b 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -284,7 +284,7 @@ class SyncRestServlet(RestServlet):
                 "prev_batch": room.timeline.prev_batch.to_string(),
                 "limited": room.timeline.limited,
             },
-            "state": serialized_state,
+            "state": {"events": serialized_state},
             "private_user_data": {"events": private_user_data},
         }