diff --git a/mqtt_run.py b/mqtt_run.py
index 2122810..52e6dca 100644
--- a/mqtt_run.py
+++ b/mqtt_run.py
@@ -35,7 +35,7 @@ def on_message(client, userdata, msg):
 
     if msg.topic == 'display/nec/image':
         logging.debug('image message received')
-        logging.debug('Image url is: ', lastmsg)
+        logging.debug('Image url is: {}'.format(lastmsg))
 
         send_jiffy(client, lastmsg)