diff --git a/firmware/otaflash.py b/firmware/otaflash.py
index c7f51a7..2c52133 100755
--- a/firmware/otaflash.py
+++ b/firmware/otaflash.py
@@ -8,6 +8,7 @@ from websocket import WebSocketTimeoutException
 
 parser = argparse.ArgumentParser(description='Update fiatlux firmware via websocket.')
 parser.add_argument("binfile")
+parser.add_argument("address")
 
 args = parser.parse_args()
 
@@ -25,7 +26,7 @@ with open(args.binfile, "rb") as f:
     try:
         ws = websocket.WebSocket()
         print("send {}".format(args.binfile))
-        ws.connect("ws://172.16.0.1")
+        ws.connect("ws://" + args.address)
         i = 0
         bytes = f.read()
         rolling = zlib.crc32(bytes)