diff --git a/lib/application.js b/lib/application.js
index 833b582..c3edd5a 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -7,7 +7,7 @@
 
 const isGeneratorFunction = require('is-generator-function');
 const debug = require('debug')('koa:application');
-const Emitter = require('events').EventEmitter;
+const Emitter = require('events');
 const onFinished = require('on-finished');
 const response = require('./response');
 const compose = require('koa-compose');
@@ -115,9 +115,7 @@ module.exports = class Application extends Emitter {
       res.statusCode = 404;
       const ctx = this.createContext(req, res);
       onFinished(res, ctx.onerror);
-      fn(ctx).then(function() {
-        respond(ctx);
-      }).catch(ctx.onerror);
+      fn(ctx).then(() => respond(ctx)).catch(ctx.onerror);
     };
   }