1 files changed, 1 insertions, 1 deletions
diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py
index 5f512ff8bf..917762e6b6 100644
--- a/tests/federation/test_federation_sender.py
+++ b/tests/federation/test_federation_sender.py
@@ -34,7 +34,7 @@ class FederationSenderReceiptsTestCases(HomeserverTestCase):
     def make_homeserver(self, reactor, clock):
         mock_state_handler = Mock(spec=["get_current_hosts_in_room"])
         # Ensure a new Awaitable is created for each call.
-        mock_state_handler.get_current_hosts_in_room.side_effect = lambda room_Id: make_awaitable(
+        mock_state_handler.get_current_hosts_in_room.return_value = make_awaitable(
             ["test", "host2"]
         )
         return self.setup_test_homeserver(