diff --git a/lib/application.js b/lib/application.js
index 1b358b2..3d0683d 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -91,9 +91,7 @@ app.callback = function(){
   return function(req, res){
     var ctx = new Context(self, req, res);
 
-    co.call(ctx, gen)(function(err){
-      if (err) ctx.onerror(err);
-    });
+    co.call(ctx, gen)(ctx.onerror);
   }
 };