diff --git a/lib/application.js b/lib/application.js
index 833b582..fbea4a4 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -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);
     };
   }