diff --git a/aries_cloudagent/transport/outbound/ws.py b/aries_cloudagent/transport/outbound/ws.py
index bd32a70989..06421a2f3f 100644
--- a/aries_cloudagent/transport/outbound/ws.py
+++ b/aries_cloudagent/transport/outbound/ws.py
@@ -36,6 +36,7 @@ async def handle_message(
         payload: Union[str, bytes],
         endpoint: str,
         metadata: dict = None,
+        api_key: str = None,
     ):
         """
         Handle message from queue.