diff --git a/examples/kbdheatmap/kbdheatmap.js b/examples/kbdheatmap/kbdheatmap.js
index 96a58f8..dd4ba64 100755
--- a/examples/kbdheatmap/kbdheatmap.js
+++ b/examples/kbdheatmap/kbdheatmap.js
@@ -15,7 +15,7 @@ var ButtonRelease = x11.eventMask.ButtonRelease;
 var kbdImg = require('./node-jpg').readJpeg('./keyboard.jpg');
 var keycoords = require('./coordinates');
 
-// from https://github.com/substack/node-keysym 
+// from https://github.com/substack/node-keysym
 var keysyms = require('./keysyms').records;
 var ks2name = {};
 for (var k in keysyms)
@@ -23,18 +23,18 @@ for (var k in keysyms)
 var kk2name = {};
 
 
-x11.createClient(function(err, display) 
+x11.createClient(function(err, display)
 {
-    var X = display.client;   
-    X.require('big-requests', function(BigReq) 
+    var X = display.client;
+    X.require('big-requests', function(err, BigReq)
     {
-        X.require('render', function(Render) {
+        X.require('render', function(err, Render) {
             X.Render = Render;
             BigReq.Enable(function(err, maxLen)
             {
                 var min = display.min_keycode;
                 var max = display.max_keycode;
-		X.GetKeyboardMapping(min, max-min, function(err, list) 
+		X.GetKeyboardMapping(min, max-min, function(err, list)
                 {
 	            // map keycode to key name
 		    for (var i=0; i < list.length; ++i)
@@ -62,26 +62,26 @@ function main(X)
 
     var win = X.AllocID();
     X.CreateWindow(
-       win, root, 
-       0, 0, kbdImg.width, kbdImg.height, 
+       win, root,
+       0, 0, kbdImg.width, kbdImg.height,
        0, 0, 0, 0,
-       { 
-           backgroundPixel: white, eventMask: Exposure|KeyPress|ButtonPress  
+       {
+           backgroundPixel: white, eventMask: Exposure|KeyPress|ButtonPress
        }
     );
     X.MapWindow(win);
-    
+
     var win1 = X.AllocID();
     X.CreateWindow(
-       win1, root, 
-       0, 0, kbdImg.width, kbdImg.height, 
+       win1, root,
+       0, 0, kbdImg.width, kbdImg.height,
        0, 0, 0, 0,
-       { 
-           backgroundPixel: white, eventMask: Exposure|KeyPress|ButtonPress  
+       {
+           backgroundPixel: white, eventMask: Exposure|KeyPress|ButtonPress
        }
     );
     X.MapWindow(win1);
-  
+
     var gc = X.AllocID();
     X.CreateGC(gc, win);
 
@@ -103,15 +103,15 @@ function main(X)
             var picKbd = X.AllocID();
             X.PutImage(2, pixmapKbd, gc, kbdImg.width, kbdImg.height, 0, 0, 0, 24, kbdImg.data);
             Render.CreatePicture(picKbd, pixmapKbd, Render.rgb24);
-            
+
             var pixmapHeat = X.AllocID();
             X.CreatePixmap(pixmapHeat, win, 32, kbdImg.width, kbdImg.height);
             var picHeat = X.AllocID();
             Render.CreatePicture(picHeat, pixmapHeat, Render.rgba32);
-            
+
             var picWin = X.AllocID();
             Render.CreatePicture(picWin, win, Render.rgb24);
-            
+
             var picWin1 = X.AllocID();
             Render.CreatePicture(picWin1, win1, Render.rgb24);
 
@@ -135,12 +135,12 @@ function main(X)
                     mindist = dist;
                 }
             }
-            
+
             Render.Composite(3, picKbd, 0, picWin, 0, 0, 0, 0, 0, 0, kbdImg.width, kbdImg.height);
             Render.Composite(3, picHeatPush, 0, picWin, 0, 0, 0, 0, x -150/2, y-150/2, 150, 150);
 
         } if (ev.type == 2) {
-           
+
             var name = kk2name[ev.keycode];
             for (var n in name)
             {
@@ -152,7 +152,7 @@ function main(X)
                     Render.Composite(3, picHeatPush, 0, picHeat, 0, 0, 0, 0, pt[0] -150/2, pt[1]-150/2, 150, 150);
                     Render.Composite(3, picHeatPush, 0, picWin1, 0, 0, 0, 0, pt[0] -150/2, pt[1]-150/2, 150, 150);
 
- 
+
                     break;
                 } else {
                     //console.log(name);
diff --git a/examples/opengl/glxgears.js b/examples/opengl/glxgears.js
index cff19b2..2d4392c 100644
--- a/examples/opengl/glxgears.js
+++ b/examples/opengl/glxgears.js
@@ -294,7 +294,7 @@ x11.createClient(function(error, display) {
     var root = display.screen[0].root;
     var width = 500;
     var height = 500;
-    X.require('glx', function(GLX) {
+    X.require('glx', function(err, GLX) {
         var depth = 24;
         findBestVisual(display, function(err, visual) {
 
diff --git a/examples/opengl/test1.js b/examples/opengl/test1.js
index 60d37c6..b8f6eac 100644
--- a/examples/opengl/test1.js
+++ b/examples/opengl/test1.js
@@ -13,7 +13,7 @@ var listId = 1;
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('glx', function(GLX) {
+    X.require('glx', function(err, GLX) {
         var visual = 0;
         var visuals = display.screen[0].depths[24];
         for (visual in visuals) {
diff --git a/examples/opengl/tp2.js b/examples/opengl/tp2.js
index 0864856..44503c2 100644
--- a/examples/opengl/tp2.js
+++ b/examples/opengl/tp2.js
@@ -304,7 +304,7 @@ x11.createClient(function(err, display) {
     var root = display.screen[0].root;
     var width = 1000;
     var height = 1000;
-    X.require('glx', function(GLX) {
+    X.require('glx', function(err, GLX) {
         var visual = 0xa1;
         var win = X.AllocID();
         X.CreateWindow(win, root, 0, 0, width, height, 0, 0, 0, 0, { eventMask: eventmask });
diff --git a/examples/opengl/triangle.js b/examples/opengl/triangle.js
index d1c60f7..7abbc85 100644
--- a/examples/opengl/triangle.js
+++ b/examples/opengl/triangle.js
@@ -8,7 +8,7 @@ for(var i=0; i < 20000; ++i) {
 var xclient = x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('glx', function(GLX) {
+    X.require('glx', function(err, GLX) {
         var screen = 0;
         var isDirect = 0;
         var ctx = X.AllocID();
diff --git a/examples/paint.js b/examples/paint.js
index f4900bb..5d666ff 100644
--- a/examples/paint.js
+++ b/examples/paint.js
@@ -10,10 +10,10 @@ var gradNo = 0;
 var xclient = x11.createClient(function(err, display) {
     X = display.client;
     var root = display.screen[0].root;
-    X.require('render', function(rendExt) {
+    X.require('render', function(err, rendExt) {
         Render = rendExt;
         var wid = X.AllocID();
-        
+
         var white = display.screen[0].white_pixel;
         var black = display.screen[0].black_pixel;
         X.CreateWindow(wid, root, 10, 10, 400, 300, 0, 0, 0, 0, { backgroundPixel: white, eventMask: PointerMotion|ButtonPress|ButtonRelease });
@@ -36,8 +36,8 @@ var xclient = x11.createClient(function(err, display) {
 
         function draw(x, y) {
             Render.Composite(3, pictGrad[gradNo], 0, pict, 0, 0, 0, 0, x-50, y-50, 100, 100);
-        }        
-  
+        }
+
         X.on('event', function(ev) {
             if (ev.type == 4 && ev.keycode == 1)
                 pressed = true;
@@ -45,14 +45,14 @@ var xclient = x11.createClient(function(err, display) {
                 pressed = false;
             else if (ev.type == 5 && ev.keycode == 4)
             {
-                gradNo--; 
+                gradNo--;
                 if (gradNo < 0)
                     gradNo = 0;
                 console.log(gradNo);
             }
             else if (ev.type == 5 && ev.keycode == 5)
             {
-                gradNo++; 
+                gradNo++;
                 if (gradNo > 9)
                     gradNo = 9;
                 console.log(gradNo);
diff --git a/examples/png/test.js b/examples/png/test.js
index 943d70a..08aa934 100644
--- a/examples/png/test.js
+++ b/examples/png/test.js
@@ -7,7 +7,7 @@ var Exposure = x11.eventMask.Exposure;
 x11.createClient(function(err, display)
 {
   var X = display.client;
-  X.require('render', function(Render) {
+  X.require('render', function(err, Render) {
     var root = display.screen[0].root;
     main(root, X, Render);
   });
@@ -15,7 +15,7 @@ x11.createClient(function(err, display)
 
 
 function main(root, X, Render) {
-  
+
   var win, picWin, pic, gc;
 
   win = X.AllocID();
@@ -39,7 +39,7 @@ function main(root, X, Render) {
   Render.CreatePicture(logoPicture, logoPixmap, Render.rgb24);
   var winPicture = X.AllocID();
   Render.CreatePicture(winPicture, win, Render.rgb24);
-      
+
   X.on('event', function(ev) {
     if (ev.name == 'Expose')
       Render.Composite(3, logoPicture, 0, winPicture, 0, 0, 0, 0, 0, 0, logo.width, logo.height);
diff --git a/examples/simple/gradients.js b/examples/simple/gradients.js
index 0b6d27e..9e4f017 100644
--- a/examples/simple/gradients.js
+++ b/examples/simple/gradients.js
@@ -9,21 +9,21 @@ var x11 = require('../../lib');
 x11.createClient(
     function(err, display) {
         var X = display.client;
-            X.require('render', function(Render) {
+            X.require('render', function(err, Render) {
 
             var root = display.screen[0].root;
             var win = X.AllocID();
             var white = display.screen[0].white_pixel;
             var black = display.screen[0].black_pixel;
-            X.CreateWindow(win, root, 0, 0, 500, 500, 0, 0, 0, 0, 
-            { 
-                  backgroundPixel: white, 
+            X.CreateWindow(win, root, 0, 0, 500, 500, 0, 0, 0, 0,
+            {
+                  backgroundPixel: white,
                   eventMask: x11.eventMask.Exposure | x11.eventMask.ButtonPress | x11.eventMask.PointerMotion
             });
             X.MapWindow(win);
 
             var picture = X.AllocID();
-            Render.CreatePicture(picture, win, Render.rgb24, { polyEdge: 1, polyMode: 0 } ); 
+            Render.CreatePicture(picture, win, Render.rgb24, { polyEdge: 1, polyMode: 0 } );
             var pixmap = X.AllocID();
             X.CreatePixmap(pixmap, win, 32, 2500, 2500);
             var pix_pict = X.AllocID();
@@ -34,30 +34,30 @@ x11.createClient(
             //RenderRadialGradient(pic_grad, [0,0], [1000,100], 10, 1000,
             //RenderConicalGradient(pic_grad, [250,250], 360,
                 [
-                  [0,   [0,0,0,0x3000 ] ], 
-                  [0.1, [0xfff, 0, 0xffff, 0x1000] ] , 
-                  [0.25, [0xffff, 0, 0xfff, 0x3000] ] , 
-                  [0.5, [0xffff, 0, 0xffff, 0x4000] ] , 
-                  [1,   [0xffff, 0xffff, 0, 0x8000] ] 
+                  [0,   [0,0,0,0x3000 ] ],
+                  [0.1, [0xfff, 0, 0xffff, 0x1000] ] ,
+                  [0.25, [0xffff, 0, 0xfff, 0x3000] ] ,
+                  [0.5, [0xffff, 0, 0xffff, 0x4000] ] ,
+                  [1,   [0xffff, 0xffff, 0, 0x8000] ]
                 ]);
 
             var pic_grad1 = X.AllocID();
 
             Render.ConicalGradient(pic_grad1, [250,250], 10,
                 [
-                  [0,   [0,0,0,0x5000 ] ], 
-                  [0.1, [0xfff, 0, 0xffff, 0x3000] ] , 
-                  [0.25, [0xffff, 0, 0xfff, 0x2000] ] , 
-                  [0.5, [0xffff, 0, 0xffff, 0x1000] ] , 
-                  [1,   [0xffff, 0xffff, 0, 0x8000] ] 
+                  [0,   [0,0,0,0x5000 ] ],
+                  [0.1, [0xfff, 0, 0xffff, 0x3000] ] ,
+                  [0.25, [0xffff, 0, 0xfff, 0x2000] ] ,
+                  [0.5, [0xffff, 0, 0xffff, 0x1000] ] ,
+                  [1,   [0xffff, 0xffff, 0, 0x8000] ]
                 ]);
 
             var pic_grad2 = X.AllocID();
             Render.RadialGradient(pic_grad2, [250,250], [250,250], 0, 250,
                 [
-                  [0,   [0,0,0,0x5000 ] ], 
+                  [0,   [0,0,0,0x5000 ] ],
                   [0.99,   [0xffff, 0xffff, 0, 0xffff] ],
-                  [1,   [0xffff, 0xffff, 0, 0x0] ] 
+                  [1,   [0xffff, 0xffff, 0, 0x0] ]
                 ]);
 
             var pixmap1 = X.AllocID();
@@ -112,7 +112,7 @@ x11.createClient(
                    draw();
                 } else {
                    draw();
-                }                  
+                }
             });
         });
      }
diff --git a/examples/simple/render.js b/examples/simple/render.js
index 7f56075..c0f046f 100644
--- a/examples/simple/render.js
+++ b/examples/simple/render.js
@@ -4,7 +4,7 @@ var PointerMotion = x11.eventMask.PointerMotion;
 var xclient = x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    display.client.require('render', function(Render) {
+    display.client.require('render', function(err, Render) {
         var wid = X.AllocID();
         var white = display.screen[0].white_pixel;
         varblack = display.screen[0].black_pixel;
@@ -24,8 +24,8 @@ var xclient = x11.createClient(function(err, display) {
 
         function draw(x, y) {
             Render.Composite(3, pictGrad, 0, pict, 0, 0, 0, 0, x-26, y-26, 52, 52);
-        }        
-  
+        }
+
         X.on('event', function(ev) {
            draw(ev.x, ev.y);
         });
diff --git a/examples/simple/text/render-glyph.js b/examples/simple/text/render-glyph.js
index 748e98a..d2a633c 100644
--- a/examples/simple/text/render-glyph.js
+++ b/examples/simple/text/render-glyph.js
@@ -39,7 +39,7 @@ function padWidth(buf, width) {
 var xclient = x11.createClient({ debug: true }, function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    display.client.require('render', function(Render) {
+    display.client.require('render', function(err, Render) {
         var wid = X.AllocID();
         var white = display.screen[0].white_pixel;
         varblack = display.screen[0].black_pixel;
diff --git a/examples/smoketest/applewm.js b/examples/smoketest/applewm.js
index ba376c5..9770df6 100644
--- a/examples/smoketest/applewm.js
+++ b/examples/smoketest/applewm.js
@@ -3,18 +3,18 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('apple-wm', function(AppleWM) {
+    X.require('apple-wm', function(err, AppleWM) {
         //AppleWM.SetFrontProcess();
-        //AppleWM.CanQuit(true);        
+        //AppleWM.CanQuit(true);
         AppleWM.SelectInput(AppleWM.NotifyMask.All)
-        
+
         /*
         for (level in AppleWM.WindowLevel)
         {
             var win = X.AllocID();
             X.CreateWindow(win, root, 0, 0, 300, 300);
             X.MapWindow(win);
-            X.ChangeProperty(0, win, X.atoms.WM_NAME, X.atoms.STRING, 8, level);            
+            X.ChangeProperty(0, win, X.atoms.WM_NAME, X.atoms.STRING, 8, level);
             AppleWM.SetWindowLevel(win, AppleWM.WindowLevel[level]);
         };
         */
@@ -22,7 +22,7 @@ x11.createClient(function(err, display) {
             var win1 = X.AllocID();
             X.CreateWindow(win1, root, 0, 0, 300, 300);
             X.MapWindow(win1);
-            X.ChangeProperty(0, win1, X.atoms.WM_NAME, X.atoms.STRING, 8, "parent");            
+            X.ChangeProperty(0, win1, X.atoms.WM_NAME, X.atoms.STRING, 8, "parent");
             var win2 = X.AllocID();
             X.CreateWindow(win2, root, 0, 0, 200, 200);
             X.MapWindow(win2);
@@ -37,12 +37,12 @@ x11.createClient(function(err, display) {
          // (screen, window, frameClass, attr, ix, iy, iw, ih, ox, oy, ow, oh, titleLength)
          var gc = X.AllocID();
          X.CreateGC(gc, win);
-        
-         function r(v) { var res =  parseInt(Math.random()*v); console.log(res); return res;} 
+
+         function r(v) { var res =  parseInt(Math.random()*v); console.log(res); return res;}
          function df() { X.PolyFillRectangle(win, gc, [0, 0, 1000, 1000]); AppleWM.FrameDraw(0, win, 65535, r(65535), 30, 30, 500, 50, 0, 0, 550, 100, "title title");}
          //setInterval(df, 100);
          X.on('event', function(ev) { console.log("Event", ev); df(); });
     });
     X.on('error', function(err) { console.log("Error", err); });
- 
+
 });
diff --git a/examples/smoketest/compositetest.js b/examples/smoketest/compositetest.js
index 53ce1ec..76f75ef 100644
--- a/examples/smoketest/compositetest.js
+++ b/examples/smoketest/compositetest.js
@@ -3,8 +3,8 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('composite', function(Composite) {
-      X.require('damage', function(Damage) {
+    X.require('composite', function(err, Composite) {
+      X.require('damage', function(err, Damage) {
         var wid = parseInt(process.argv[2]);
         //Composite.GetOverlayWindow(wid, function(err, overlayid) {
         //  console.log("OVERLAY:", err, overlayid);
diff --git a/examples/smoketest/damagetest.js b/examples/smoketest/damagetest.js
index 9aea817..72be79a 100644
--- a/examples/smoketest/damagetest.js
+++ b/examples/smoketest/damagetest.js
@@ -3,7 +3,7 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('damage', function(Damage) {
+    X.require('damage', function(err, Damage) {
         console.log(Damage);
         var id = parseInt(process.argv[2]);
         var damage = X.AllocID();
@@ -14,5 +14,5 @@ x11.createClient(function(err, display) {
         });
     });
     X.on('error', function(err) { console.log(err); });
- 
+
 });
diff --git a/examples/smoketest/fixestest.js b/examples/smoketest/fixestest.js
index 84b0a1a..d1bd456 100644
--- a/examples/smoketest/fixestest.js
+++ b/examples/smoketest/fixestest.js
@@ -3,7 +3,7 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('fixes', function(Fixes) {
+    X.require('fixes', function(err, Fixes) {
         console.log(Fixes);
         var win = X.AllocID();
         X.CreateWindow(win, root, 0, 0, 100, 100);
diff --git a/examples/smoketest/putimage1.js b/examples/smoketest/putimage1.js
index 9adb5e1..71f354b 100644
--- a/examples/smoketest/putimage1.js
+++ b/examples/smoketest/putimage1.js
@@ -23,7 +23,7 @@ x11.createClient(function(err, display) {
     if (err) throw err;
 
     var X = display.client;
-X.require('render', function(Render) {
+X.require('render', function(err, Render) {
 
     var root = display.screen[0].root;
     var white = display.screen[0].white_pixel;
diff --git a/examples/smoketest/randr.js b/examples/smoketest/randr.js
index 0700483..4684217 100644
--- a/examples/smoketest/randr.js
+++ b/examples/smoketest/randr.js
@@ -3,7 +3,7 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('randr', function(Randr) {
+    X.require('randr', function(err, Randr) {
         //console.log(Randr);
         //Randr.QueryVersion(1, 4, console.log);
         Randr.SelectInput(root, Randr.NotifyMask.ScreenChange);
diff --git a/examples/smoketest/shapetest.js b/examples/smoketest/shapetest.js
index 4ee6070..31ba286 100644
--- a/examples/smoketest/shapetest.js
+++ b/examples/smoketest/shapetest.js
@@ -3,11 +3,11 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('shape', function(Shape) {
+    X.require('shape', function(err, Shape) {
         var win = X.AllocID();
         X.CreateWindow(win, root, 0, 0, 200, 200);
         var gc = X.AllocID();
-        X.CreateGC(gc, win);     
+        X.CreateGC(gc, win);
         //X.MapWindow(win);
         Shape.SelectInput(win, 1);
         Shape.InputSelected(win, function(err, isSelected) {
@@ -23,5 +23,5 @@ x11.createClient(function(err, display) {
         });
     });
     X.on('error', function(err) { console.log(err); });
- 
+
 });
diff --git a/examples/smoketest/sstest.js b/examples/smoketest/sstest.js
index 2e4688f..40de289 100644
--- a/examples/smoketest/sstest.js
+++ b/examples/smoketest/sstest.js
@@ -7,7 +7,7 @@ x11.createClient(function(err, display) {
     X.SetScreenSaver(20, 10, 2, 2);
 
 
-    X.require('screen-saver', function(SS) {
+    X.require('screen-saver', function(err, SS) {
         SS.SelectInput(root, SS.eventMask.Notify|SS.eventMask.Cycle);
         //console.log(SS);
         //setTimeout(function() {
@@ -15,7 +15,7 @@ x11.createClient(function(err, display) {
         //}, 5000);
         setInterval(function() {
         SS.QueryInfo(root, function(err, info) {
-            console.log(info.until);    
+            console.log(info.until);
             //SS.SelectInput(root, SS.eventMask.Notify|SS.eventMask.Cycle);
         });
         }, 1000);
@@ -24,5 +24,5 @@ x11.createClient(function(err, display) {
         });
     });
     X.on('error', function(err) { console.log(err); });
- 
+
 });
diff --git a/examples/smoketest/transpwindow.js b/examples/smoketest/transpwindow.js
index 30abafb..32da418 100644
--- a/examples/smoketest/transpwindow.js
+++ b/examples/smoketest/transpwindow.js
@@ -25,18 +25,18 @@ x11.createClient(function(err, display) {
 
     var cmid = X.AllocID();
     var depth = 32;
-    X.CreateColormap(cmid, root, visual, 0); // 0=AllocNone, 1 AllocAll 
-    
+    X.CreateColormap(cmid, root, visual, 0); // 0=AllocNone, 1 AllocAll
+
     X.CreateWindow(wid, root, 10, 10, 168, 195, 1, depth, 1, visual, { eventMask: x11.eventMask.Exposure, colormap: cmid, backgroundPixel: 0, borderPixel: 0 });
     X.MapWindow(wid);
 
     var gc = X.AllocID();
-    X.require('render', function(Render) {
+    X.require('render', function(err, Render) {
 
         var pict = X.AllocID();
         Render.CreatePicture(pict, wid, Render.rgba32);
         var gradients = [];
-        
+
         function randomLinear() {
             var stops = [];
             for (var i=0; i<3; ++i)
@@ -49,8 +49,8 @@ x11.createClient(function(err, display) {
                     parseInt(Math.random()*65535),
                     parseInt(Math.random()*65535),
                     parseInt(Math.random()*65535)]]);
-    
-            console.log(colors); 
+
+            console.log(colors);
 
             var gradient = X.AllocID();
             Render.LinearGradient(gradient, [0, 0], [100+parseInt(Math.random()*500), parseInt(100+Math.random()*300)], colors);
@@ -64,7 +64,7 @@ x11.createClient(function(err, display) {
             var gid = parseInt(Math.random()*gradients.length);
             console.log(gradients[gid]);
             Render.Composite(1, gradients[gid], 0, pict, 0, 0, 0, 0, 0, 0, 400, 300);
-        }, 2000); 
+        }, 2000);
     });
     //X.CreateGC(gc, wid, { foreground: black, background: white } );
     //setInterval(function() {
diff --git a/examples/smoketest/xcmisc.js b/examples/smoketest/xcmisc.js
index 0516265..18069f8 100644
--- a/examples/smoketest/xcmisc.js
+++ b/examples/smoketest/xcmisc.js
@@ -3,7 +3,7 @@ var x11 = require('../../lib');
 x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    X.require('xc-misc', function(Misc) {
+    X.require('xc-misc', function(err, Misc) {
         var xid = X.AllocID();
         console.log("first ID from connection: " + xid);
         debugger;
@@ -15,5 +15,5 @@ x11.createClient(function(err, display) {
         });
     });
     X.on('error', function(err) { console.log("Error", err); });
- 
+
 });
diff --git a/examples/smoketest/xtesttest.js b/examples/smoketest/xtesttest.js
index 10e3874..d7c215e 100644
--- a/examples/smoketest/xtesttest.js
+++ b/examples/smoketest/xtesttest.js
@@ -3,7 +3,7 @@ var x11 = require('../../lib');
 var xclient = x11.createClient(function(err, display) {
     var X = display.client;
     var root = display.screen[0].root;
-    display.client.require('xtest', function(Test) {
+    display.client.require('xtest', function(err, Test) {
         console.log(Test);
         setInterval(function() {
            Test.FakeInput(Test.KeyPress, 65, 0, root, 0, 0);   // space
diff --git a/examples/vncviewer/vncgui.js b/examples/vncviewer/vncgui.js
index 7c897b9..725bf4e 100644
--- a/examples/vncviewer/vncgui.js
+++ b/examples/vncviewer/vncgui.js
@@ -30,8 +30,8 @@ var KeyPress = x11.eventMask.KeyPress;
 var KeyRelease = x11.eventMask.KeyRelease;
 
 x11.createClient(function(err, display) {
-    var X = display.client;   
-    X.require('big-requests', function(BigReq) {
+    var X = display.client;
+    X.require('big-requests', function(err, BigReq) {
         BigReq.Enable(function(err, maxLen) {
             var keycode2keysym = [];
             var min = display.min_keycode;
@@ -54,19 +54,19 @@ x11.createClient(function(err, display) {
 
             var wid = X.AllocID();
             X.CreateWindow(wid, root, 0, 0, r.width, r.height);
-            X.ChangeWindowAttributes(wid, { 
-                backgroundPixel: black, 
-                eventMask: Exposure|PointerMotion|ButtonPress|ButtonRelease|KeyPress|KeyRelease 
+            X.ChangeWindowAttributes(wid, {
+                backgroundPixel: black,
+                eventMask: Exposure|PointerMotion|ButtonPress|ButtonRelease|KeyPress|KeyRelease
             });
             X.ChangeProperty(0, wid, X.atoms.WM_NAME, X.atoms.STRING, 8, r.title);
             X.MapWindow(wid);
 
             var gc = X.AllocID();
             X.CreateGC(gc, wid, { foreground: black, background: white } );
-            
+
             //var pixbuf = X.AllocID();
             //X.CreatePixmap(pixbuf, wid, 32, r.width, r.height);
-            //var pic = X.AllocID(); 
+            //var pic = X.AllocID();
             //Render.CreatePicture(pic, pixbuf, Render.rgba32);
 
             var buttonsState = 0;
@@ -86,7 +86,7 @@ x11.createClient(function(err, display) {
                     // set button bit
                     if (ev.type == 4)
                         buttonsState |= buttonBit;
-                    else 
+                    else
                         buttonsState &= ~buttonBit;
                     r.pointerEvent(ev.x, ev.y, buttonsState);
                 } else if (ev.type == 2 || ev.type == 3) {
@@ -121,7 +121,7 @@ x11.createClient(function(err, display) {
             });
 
         }); // r.on('connect)
-    }); // GetKeyboardMapping 
+    }); // GetKeyboardMapping
 }); // BigReq.Enable
 
 }); // require('big-requests
diff --git a/examples/windowmanager/wm.js b/examples/windowmanager/wm.js
index dcaebdd..384846e 100644
--- a/examples/windowmanager/wm.js
+++ b/examples/windowmanager/wm.js
@@ -80,7 +80,7 @@ function ManageWindow(wid)
 
 x11.createClient(function(err, display) {
     X = display.client;
-    X.require('render', function(Render) {
+    X.require('render', function(err, Render) {
     X.Render = Render;
 
     root = display.screen[0].root;
diff --git a/lib/ext/apple-wm.js b/lib/ext/apple-wm.js
index 6e6db66..dd9e3c1 100644
--- a/lib/ext/apple-wm.js
+++ b/lib/ext/apple-wm.js
@@ -18,10 +18,10 @@ var xutil = require('../xutil');
 #define X_AppleWMAttachTransient        13
 */
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('Apple-WM', function(err, ext) {  
+    X.QueryExtension('Apple-WM', function(err, ext) {
 
         if (!ext.present)
             callback(new Error('extension not available'));
@@ -32,7 +32,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCS', [ext.majorOpcode, 0, 1]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('SSL');    
+                    var res = buf.unpack('SSL');
                     return res;
                 },
                 cb
@@ -52,7 +52,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSSSSSSSSSSS', [ext.majorOpcode, 1, 6, frame_class, frame_rect, ix, iy, iw, ih, ox, oy, ow, oh, cb]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('SSSS');    
+                    var res = buf.unpack('SSSS');
                     return {
                         x: res[0],
                         y: res[1],
@@ -64,7 +64,7 @@ exports.requireExt = function(display, callback)
             ];
             X.pack_stream.flush();
         }
- 
+
         ext.FrameHitTest = function(frame_class, px, py, ix, iy, iw, ih, ox, oy, ow, oh, cb)
         {
             X.seq_num++;
@@ -80,7 +80,7 @@ exports.requireExt = function(display, callback)
         }
 
 
-// from /usr/include/Xplugin.h  
+// from /usr/include/Xplugin.h
         ext.FrameClass = {
             DecorLarge: 1,
             Reserved1: 2,
@@ -107,7 +107,7 @@ exports.requireExt = function(display, callback)
             CloseBoxClicked: 0x800,
             CollapseBoxClicked: 0x1000,
             ZoomBoxClicked: 0x2000,
-            GrowBox: 0x4000  
+            GrowBox: 0x4000
         };
 
         ext.FrameDraw = function(screen, window, frameClass, attr, ix, iy, iw, ih, ox, oy, ow, oh, title)
@@ -189,7 +189,7 @@ exports.requireExt = function(display, callback)
            var reqlen = 8;
            var extlength = 0;
            items.forEach(function(i) {
-             
+
            });
         }
 
@@ -209,13 +209,13 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         }
 
-        callback(ext);
+        callback(null, ext);
         /*
         ext.QueryVersion(function(err, vers) {
             ext.major = vers[0];
             ext.minor = vers[1];
             ext.patch = vers[2];
-            callback(ext);
+            callback(null, ext);
         });
         */
 
@@ -248,7 +248,7 @@ exports.requireExt = function(display, callback)
             CopyToPasteboard: 0
           }
         };
-    
+
         X.eventParsers[ext.firstEvent + ext.events.AppleWMControllerNotify] =
         X.eventParsers[ext.firstEvent + ext.events.AppleWMActivationNotify] =
         X.eventParsers[ext.firstEvent + ext.events.AppleWMPasteboardNotify] = function(type, seq, extra, code, raw)
diff --git a/lib/ext/big-requests.js b/lib/ext/big-requests.js
index 19b61e9..8f91d3d 100644
--- a/lib/ext/big-requests.js
+++ b/lib/ext/big-requests.js
@@ -1,11 +1,11 @@
 // http://www.x.org/releases/X11R7.6/doc/bigreqsproto/bigreq.html
 
 // TODO: move to templates
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('BIG-REQUESTS', function(err, ext) {  
-        
+    X.QueryExtension('BIG-REQUESTS', function(err, ext) {
+
         if (!ext.present)
             return callback(new Error('extension not available'));
 
@@ -21,6 +21,6 @@ exports.requireExt = function(display, callback)
             ];
             X.pack_stream.flush();
         }
-        callback(ext);
+        callback(null, ext);
     });
 }
diff --git a/lib/ext/damage.js b/lib/ext/damage.js
index c4aa996..bfebcc8 100644
--- a/lib/ext/damage.js
+++ b/lib/ext/damage.js
@@ -61,6 +61,8 @@ exports.requireExt = function(display, callback)
         }
 
         ext.QueryVersion(1, 1, function(err, vers) {
+            if (err)
+                return callback(err);
             ext.major = vers[0];
             ext.minor = vers[1];
             callback(null, ext);
diff --git a/lib/ext/dpms.js b/lib/ext/dpms.js
index 2aeefdf..a607fd3 100644
--- a/lib/ext/dpms.js
+++ b/lib/ext/dpms.js
@@ -94,7 +94,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         };
 
-        callback(ext);
+        callback(null, ext);
     });
 };
 
diff --git a/lib/ext/fixes.js b/lib/ext/fixes.js
index 434a8ee..8bb0686 100644
--- a/lib/ext/fixes.js
+++ b/lib/ext/fixes.js
@@ -7,7 +7,7 @@ function parse_rectangle(buf, pos) {
     if (!pos) {
         pos = 0;
     }
-    
+
     return {
         x : buf[pos],
         y : buf[pos + 1],
@@ -16,10 +16,10 @@ function parse_rectangle(buf, pos) {
     }
 }
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('XFIXES', function(err, ext) {  
+    X.QueryExtension('XFIXES', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
@@ -30,7 +30,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSLL', [ext.majorOpcode, 0, 3, clientMaj, clientMin]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('LL');                 
+                    var res = buf.unpack('LL');
                     return res;
                 },
                 callback
@@ -68,7 +68,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack(format, args);
             X.pack_stream.flush();
         }
-        
+
         ext.CreateRegionFromWindow = function(region, wid, kind) {
             X.seq_num ++;
             X.pack_stream.pack('CCSLLCxxx', [ ext.majorOpcode, 7, 4, region, wid, kind ]);
@@ -92,7 +92,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSLss', [ ext.majorOpcode, 17, 3, region, dx, dy ]);
             X.pack_stream.flush();
         }
-        
+
         ext.FetchRegion = function(region, cb) {
             X.seq_num ++;
             X.pack_stream.pack('CCSL', [ ext.majorOpcode, 19, 2, region ]);
@@ -110,7 +110,7 @@ exports.requireExt = function(display, callback)
                     for (var i = 0; i < n_rectangles; ++ i) {
                         reg.rectangles.push(parse_rectangle(res, 4 + (i << 2)));
                     }
-                    
+
                     return reg;
                 },
                 cb
@@ -120,16 +120,18 @@ exports.requireExt = function(display, callback)
         }
 
         ext.QueryVersion(5, 0, function(err, vers) {
+            if (err)
+                return callback(err);
             ext.major = vers[0];
             ext.minor = vers[1];
-            callback(ext);
+            callback(null, ext);
         });
 
         ext.events = {
             DamageNotify: 0
         }
 
-        X.eventParsers[ext.firstEvent + ext.events.DamageNotify] = function(type, seq, extra, code, raw) 
+        X.eventParsers[ext.firstEvent + ext.events.DamageNotify] = function(type, seq, extra, code, raw)
         {
             var event = {};
             event.level = code;
@@ -139,16 +141,16 @@ exports.requireExt = function(display, callback)
             event.damage = values[0];
             event.time = values[1];
             event.area = {
-              x: values[2],                        
-              y: values[3],                        
-              w: values[4],                        
-              h: values[5]                        
+              x: values[2],
+              y: values[3],
+              w: values[4],
+              h: values[5]
             };
             event.geometry = {
-              x: values[6],                        
-              y: values[7],                        
-              w: values[8],                        
-              h: values[9]                        
+              x: values[6],
+              y: values[7],
+              w: values[8],
+              h: values[9]
             };
             event.name = 'DamageNotify';
             return event;
diff --git a/lib/ext/glx.js b/lib/ext/glx.js
index f60ecf5..df3c42d 100644
--- a/lib/ext/glx.js
+++ b/lib/ext/glx.js
@@ -319,7 +319,7 @@ exports.requireExt = function(display, callback)
 	  };
 	});
 
-        callback(ext);
+        callback(null, ext);
     });
 }
 
diff --git a/lib/ext/randr.js b/lib/ext/randr.js
index fb69629..6516518 100644
--- a/lib/ext/randr.js
+++ b/lib/ext/randr.js
@@ -3,15 +3,15 @@
 var x11 = require('..');
 // TODO: move to templates
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('RANDR', function(err, ext) {  
+    X.QueryExtension('RANDR', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
 
-        //ext.ReportLevel	= { 
+        //ext.ReportLevel	= {
         //};
 
         ext.QueryVersion = function(clientMaj, clientMin, callback)
@@ -198,7 +198,7 @@ exports.requireExt = function(display, callback)
 
                         pos += res_modes[i + 11];
                     }
-                    
+
                     return resources;
                 },
                 cb
@@ -223,7 +223,7 @@ exports.requireExt = function(display, callback)
                         height : res[4],
                         mode : res[5],
                         rotation : res[6],
-                        rotations : res[7] 
+                        rotations : res[7]
                     };
 
                     pos += 24;
@@ -239,7 +239,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         },
 
-        X.eventParsers[ext.firstEvent + ext.events.RRScreenChangeNotify] = function(type, seq, extra, code, raw) 
+        X.eventParsers[ext.firstEvent + ext.events.RRScreenChangeNotify] = function(type, seq, extra, code, raw)
         {
 	    var event = {};
 	    event.raw = raw;
@@ -263,6 +263,6 @@ exports.requireExt = function(display, callback)
 	    return event;
         };
 
-        callback(ext);
+        callback(null, ext);
     });
 }
diff --git a/lib/ext/render.js b/lib/ext/render.js
index e99629d..cf01c39 100644
--- a/lib/ext/render.js
+++ b/lib/ext/render.js
@@ -530,6 +530,8 @@ exports.requireExt = function(display, callback)
             // 11 - colormap or none
 
             ext.QueryPictFormat(function(err, formats) {
+                if (err)
+                    return callback(err);
                 for (var i=0; i < formats.formats.length; ++i) {
                     var f = formats.formats[i];
                     if (f[2] == 1 && f[10] == 1)
@@ -542,7 +544,7 @@ exports.requireExt = function(display, callback)
                     if (f[2] == 8 && f[10] == 255)
                         ext.a8 = f[0];
                 }
-                callback(ext);
+                callback(null, ext);
             });
 
             [
diff --git a/lib/ext/screen-saver.js b/lib/ext/screen-saver.js
index 89da127..82e7bc4 100644
--- a/lib/ext/screen-saver.js
+++ b/lib/ext/screen-saver.js
@@ -3,10 +3,10 @@
 var x11 = require('..');
 // TODO: move to templates
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('MIT-SCREEN-SAVER', function(err, ext) {  
+    X.QueryExtension('MIT-SCREEN-SAVER', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
@@ -18,7 +18,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSCCxx', [ext.majorOpcode, 0, 2, clientMaj, clientMin]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('CC');                 
+                    var res = buf.unpack('CC');
                     return res;
                 },
                 cb
@@ -26,18 +26,18 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         }
 
-        ext.State = { 
+        ext.State = {
             Off: 0,
 	    On: 1,
             Disabled: 2
         };
 
-        ext.Kind = { 
+        ext.Kind = {
             Blanked: 0,
 	    Internal: 1,
             External: 2
         };
-        
+
         ext.QueryInfo = function(drawable, callback)
         {
             X.seq_num++;
@@ -51,7 +51,7 @@ exports.requireExt = function(display, callback)
                     info.until = res[1];
                     info.idle = res[2];
                     info.eventMask = res[3];
-                    info.kind = res[4]             
+                    info.kind = res[4]
                     return info;
                 },
                 callback
@@ -73,10 +73,11 @@ exports.requireExt = function(display, callback)
         }
 
         ext.QueryVersion(1, 1, function(err, vers) {
-            
+            if (err)
+                return callback(err);
             ext.major = vers[0];
             ext.minor = vers[1];
-            callback(ext);
+            callback(null, ext);
         });
 
         ext.events = {
@@ -89,7 +90,7 @@ exports.requireExt = function(display, callback)
             Cycle: 2
         }
 
-        X.eventParsers[ext.firstEvent + ext.events.ScreenSaverNotify] = function(type, seq, extra, code, raw) 
+        X.eventParsers[ext.firstEvent + ext.events.ScreenSaverNotify] = function(type, seq, extra, code, raw)
         {
             var event = {};
             event.state = code;
diff --git a/lib/ext/shape.js b/lib/ext/shape.js
index acb54ba..f328c11 100644
--- a/lib/ext/shape.js
+++ b/lib/ext/shape.js
@@ -3,7 +3,7 @@
 var x11 = require('..');
 // TODO: move to templates
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
         function captureStack()
         {
@@ -14,12 +14,12 @@ exports.requireExt = function(display, callback)
         }
 
     var X = display.client;
-    X.QueryExtension('SHAPE', function(err, ext) {  
+    X.QueryExtension('SHAPE', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
 
-        ext.Kind = { 
+        ext.Kind = {
             Bounding: 0,
 	    Clip: 1,
             Input: 2
@@ -40,7 +40,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSLL', [ext.majorOpcode, 0, 1]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('SS');                 
+                    var res = buf.unpack('SS');
                     return res;
                 },
                 cb
@@ -78,13 +78,13 @@ exports.requireExt = function(display, callback)
             X.pack_stream.flush();
         }
 
-        callback(ext);
-   
+        callback(null, ext);
+
         /*
         ext.QueryVersion(function(err, version) {
             ext.major = version[0];
             ext.minor = version[1];
-            callback(ext);
+            callback(null, ext);
         });
         */
     });
diff --git a/lib/ext/xc-misc.js b/lib/ext/xc-misc.js
index 1f0bc42..53aa72f 100644
--- a/lib/ext/xc-misc.js
+++ b/lib/ext/xc-misc.js
@@ -3,10 +3,10 @@
 var x11 = require('..');
 // TODO: move to templates
 
-exports.requireExt = function(display, callback) 
+exports.requireExt = function(display, callback)
 {
     var X = display.client;
-    X.QueryExtension('XC-MISC', function(err, ext) {  
+    X.QueryExtension('XC-MISC', function(err, ext) {
 
         if (!ext.present)
             return callback(new Error('extension not available'));
@@ -17,7 +17,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCSSS', [ext.majorOpcode, 0, 2, clientMaj, clientMin]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('SS');                 
+                    var res = buf.unpack('SS');
                     return res;
                 },
                 cb
@@ -31,7 +31,7 @@ exports.requireExt = function(display, callback)
             X.pack_stream.pack('CCS', [ext.majorOpcode, 1, 1]);
             X.replies[X.seq_num] = [
                 function(buf, opt) {
-                    var res = buf.unpack('LL'); 
+                    var res = buf.unpack('LL');
                     return {
                         startId: res[0],
                         count: res[1]
@@ -60,9 +60,11 @@ exports.requireExt = function(display, callback)
         }
 
         ext.QueryVersion(1, 1, function(err, vers) {
+            if (err)
+                return callback(err);
             ext.major = vers[0];
             ext.minor = vers[1];
-            callback(ext);
+            callback(null, ext);
         });
     });
 }
diff --git a/lib/xcore.js b/lib/xcore.js
index 97e3fdd..1586d67 100644
--- a/lib/xcore.js
+++ b/lib/xcore.js
@@ -592,7 +592,9 @@ module.exports.createClient = function(options, initCb)
         client.on('connect', function(display) {
             // opt-in BigReq
             if (!options.disableBigRequests) {
-                client.require('big-requests', function(BigReq) {
+                client.require('big-requests', function(err, BigReq) {
+                    if (err)
+                        return initCb(err)
                     BigReq.Enable(function(err, maxLen) {
                         display.max_request_length = maxLen;
 	                cbCalled = true;
diff --git a/test/dpms.js b/test/dpms.js
index d231d37..d184011 100644
--- a/test/dpms.js
+++ b/test/dpms.js
@@ -12,8 +12,8 @@ describe('DPMS extension', function() {
             if (!err) {
                 display = dpy;
                 X = display.client;
-                X.require('dpms', function(ext) {
-                    if (util.isError(ext)) {
+                X.require('dpms', function(err, ext) {
+                    if (err) {
                         done(ext);
                     } else {
                         dpms = ext;
diff --git a/test/randr.js b/test/randr.js
index 97d101d..683c4d1 100644
--- a/test/randr.js
+++ b/test/randr.js
@@ -11,8 +11,8 @@ describe('RANDR extension', function() {
             self.X = dpy.client;
             self.screen = dpy.screen[0];
             self.root = self.screen.root;
-            self.X.require('randr', function(ext) {
-                util.isError(ext).should.equal(false);
+            self.X.require('randr', function(err, ext) {
+                err.should.equal(null);
                 self.randr = ext;
                 /* We HAVE to QueryVersion before using it. Otherwise it does not work as expected */
                 self.randr.QueryVersion(1, 2, done);
diff --git a/test/xtest.js b/test/xtest.js
index 65c79df..a977b8f 100644
--- a/test/xtest.js
+++ b/test/xtest.js
@@ -12,8 +12,8 @@ describe('XTEST extension', function() {
             if (!err) {
                 display = dpy;
                 X = display.client;
-                X.require('xtest', function(ext) {
-                    if (util.isError(ext)) {
+                X.require('xtest', function(err, ext) {
+                    if (err) {
                         done(ext);
                     } else {
                         xtest = ext;