diff --git a/zerver/lib/actions.py b/zerver/lib/actions.py
index 7f0a948cc1..7ad74aef59 100644
--- a/zerver/lib/actions.py
+++ b/zerver/lib/actions.py
@@ -908,10 +908,7 @@ def do_set_realm_message_editing(
 
 
 def do_set_realm_notifications_stream(
-    realm: Realm,
-    stream: Optional[Stream],
-    stream_id: int,
-    acting_user: Optional[UserProfile] = None,
+    realm: Realm, stream: Optional[Stream], stream_id: int, *, acting_user: Optional[UserProfile]
 ) -> None:
     old_value = realm.notifications_stream_id
     realm.notifications_stream = stream
diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index d0bad29054..2c80843135 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -1152,7 +1152,10 @@ class NormalActionsTest(BaseAction):
         for notifications_stream, notifications_stream_id in ((stream, stream.id), (None, -1)):
             events = self.verify_action(
                 lambda: do_set_realm_notifications_stream(
-                    self.user_profile.realm, notifications_stream, notifications_stream_id
+                    self.user_profile.realm,
+                    notifications_stream,
+                    notifications_stream_id,
+                    acting_user=None,
                 )
             )
             check_realm_update("events[0]", events[0], "notifications_stream_id")