diff --git a/synapse/storage/keys.py b/synapse/storage/keys.py
index 4f990b7792..940a5f7e08 100644
--- a/synapse/storage/keys.py
+++ b/synapse/storage/keys.py
@@ -163,6 +163,7 @@ class KeyStore(SQLBaseStore):
                 "ts_valid_until_ms": ts_expires_ms,
                 "key_json": buffer(key_json_bytes),
             },
+            desc="store_server_keys_json",
         )
 
     def get_server_keys_json(self, server_keys):