diff --git a/hbd b/hbd
index 1efec94..4aaac7f 100755
--- a/hbd
+++ b/hbd
@@ -1137,11 +1137,11 @@ wss_pem = pathlib.Path(WSS_PEM)
 wss_key = pathlib.Path(WSS_KEY)
 ssl_context.load_cert_chain(wss_pem, keyfile=wss_key)
 wss_start_server = websockets.serve(ws_serve, hbd_host, WSSPORT, 
-					ssl=ssl_context, loop=loop, subprotocols="hbd")
+					ssl=ssl_context, loop=loop, subprotocols=["hbd"])
 loop.run_until_complete(wss_start_server)
 
 ws_start_server = websockets.serve(ws_serve, hbd_host, WSPORT, 
-					loop = loop, subprotocols="hbd")
+					loop = loop, subprotocols=["hbd"])
 loop.run_until_complete(ws_start_server)
 
 servthread = threading.Thread(target=serv.serve_forever)