diff --git a/client.js b/client.js
index 6b7da1d..e7161ed 100644
--- a/client.js
+++ b/client.js
@@ -311,7 +311,7 @@ Tracker.prototype._requestUdp = function (requestUrl, opts) {
     }
 
     var action = msg.readUInt32BE(0)
-    debug(requestUrl, 'UDP response, action', action)
+    debug(requestUrl + ' UDP response, action ' + action)
     switch (action) {
       case 0: // handshake
         if (msg.length < 16) {