1 files changed, 1 insertions, 1 deletions
diff --git a/tests/handlers/test_federation.py b/tests/handlers/test_federation.py
index c1558c40c3..57675fa407 100644
--- a/tests/handlers/test_federation.py
+++ b/tests/handlers/test_federation.py
@@ -656,7 +656,7 @@ class PartialJoinTestCase(unittest.FederatingHomeserverTestCase):
                         EVENT_INVITATION_MEMBERSHIP,
                     ],
                     partial_state=True,
-                    servers_in_room=["example.com"],
+                    servers_in_room={"example.com"},
                 )
             )
         )