diff --git a/lib/x11/xcore.js b/lib/x11/xcore.js
index 28cd9a6..b3c476d 100644
--- a/lib/x11/xcore.js
+++ b/lib/x11/xcore.js
@@ -87,9 +87,10 @@ XClient.prototype.terminate = function()
 // GetAtomName used as cheapest non-modifying request with reply
 // 3 - id for shortest standard atom, "ARC"
 XClient.prototype.ping = function(cb) {
+   var start = Date.now();
    this.GetAtomName(3, function(err, str) {
       if (err) return cb(err);
-      return cb();
+      return cb(null, Date.now() - start);
    });
 }