diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 6239364018..71eaeecd85 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -1617,7 +1617,7 @@ class EventsRegisterTest(ZulipTestCase):
         ])
 
         # Subscribe to a totally new stream, so it's just Hamlet on it
-        action = lambda: self.subscribe(self.example_user("hamlet"), "test_stream")  # type: Callable
+        action = lambda: self.subscribe(self.example_user("hamlet"), "test_stream")  # type: Callable[[], Any]
         events = self.do_test(action, event_types=["subscription", "realm_user"],
                               include_subscribers=include_subscribers)
         error = add_schema_checker('events[0]', events[0])