1 files changed, 4 insertions, 3 deletions
diff --git a/synapse/handlers/search.py b/synapse/handlers/search.py
index 4d40d3ac9c..9b312a1558 100644
--- a/synapse/handlers/search.py
+++ b/synapse/handlers/search.py
@@ -15,6 +15,7 @@
 
 import itertools
 import logging
+from typing import Iterable
 
 from unpaddedbase64 import decode_base64, encode_base64
 
@@ -37,7 +38,7 @@ class SearchHandler(BaseHandler):
         self.state_store = self.storage.state
         self.auth = hs.get_auth()
 
-    async def get_old_rooms_from_upgraded_room(self, room_id):
+    async def get_old_rooms_from_upgraded_room(self, room_id: str) -> Iterable[str]:
         """Retrieves room IDs of old rooms in the history of an upgraded room.
 
         We do so by checking the m.room.create event of the room for a
@@ -48,10 +49,10 @@ class SearchHandler(BaseHandler):
         The full list of all found rooms in then returned.
 
         Args:
-            room_id (str): id of the room to search through.
+            room_id: id of the room to search through.
 
         Returns:
-            Deferred[iterable[str]]: predecessor room ids
+            Predecessor room ids
         """
 
         historical_room_ids = []