diff --git a/lib/x11/ext/big-requests.js b/lib/x11/ext/big-requests.js
index 172d365..7e24cbb 100644
--- a/lib/x11/ext/big-requests.js
+++ b/lib/x11/ext/big-requests.js
@@ -4,8 +4,8 @@
 exports.requireExt = function(display, callback) 
 {
     var X = display.client;
-    X.QueryExtension('BIG-REQUESTS', function(ext) {  
-
+    X.QueryExtension('BIG-REQUESTS', function(err, ext) {  
+        
         if (!ext.present)
             callback(new Error('extension not available'));
 
diff --git a/lib/x11/ext/render.js b/lib/x11/ext/render.js
index 0758385..817e55d 100644
--- a/lib/x11/ext/render.js
+++ b/lib/x11/ext/render.js
@@ -18,7 +18,7 @@ exports.requireExt = function(display, callback)
         }
 
         var X = display.client;
-        X.QueryExtension('RENDER', function(ext) {  
+        X.QueryExtension('RENDER', function(err, ext) {  
 
             if (!ext.present)
             {
@@ -366,7 +366,7 @@ exports.requireExt = function(display, callback)
                 X.pack_stream.flush();                
             }
 
-            ext.QueryPictFormat(function(formats) {
+            ext.QueryPictFormat(function(err, formats) {
                 for (var i=0; i < formats.formats.length; ++i) {
                     var f = formats.formats[i];
                     if (f[2] == 1 && f[10] == 1)
diff --git a/lib/x11/ext/xtest.js b/lib/x11/ext/xtest.js
index f4de80e..82b0c90 100644
--- a/lib/x11/ext/xtest.js
+++ b/lib/x11/ext/xtest.js
@@ -5,7 +5,7 @@ var x11 = require('..');
 exports.requireExt = function(display, callback) 
 {
     var X = display.client;
-    X.QueryExtension('XTEST', function(ext) {  
+    X.QueryExtension('XTEST', function(err, ext) {  
 
         if (!ext.present)
             callback(new Error('extension not available'));