diff --git a/zerver/actions/message_send.py b/zerver/actions/message_send.py
index dd9edfcb12..7083206884 100644
--- a/zerver/actions/message_send.py
+++ b/zerver/actions/message_send.py
@@ -705,6 +705,7 @@ def get_active_presence_idle_user_ids(
 
 def do_send_messages(
     send_message_requests_maybe_none: Sequence[Optional[SendMessageRequest]],
+    *,
     email_gateway: bool = False,
     mark_as_read: Sequence[int] = [],
 ) -> List[int]: