diff --git a/lib/ext/xtest.js b/lib/ext/xtest.js
index 689c0b6..5ad4a66 100644
--- a/lib/ext/xtest.js
+++ b/lib/ext/xtest.js
@@ -2,10 +2,10 @@
 
 var x11 = require('..');
 // TODO: move to templates
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('XTEST', function(err, ext) {  
+    X.QueryExtension('XTEST', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
@@ -39,7 +39,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         }
 
-        callback(ext);
+        callback(null, ext);
     });
 }
-         
+