diff --git a/locale/en/about/index.md b/locale/en/about/index.md
index dad32f8837efc..e6ea76ad9625f 100644
--- a/locale/en/about/index.md
+++ b/locale/en/about/index.md
@@ -16,7 +16,7 @@ var http = require('http');
 http.createServer(function (req, res) {
   res.writeHead(200, {'Content-Type': 'text/plain'});
   res.end('Hello World\n');
-}).listen(1337, "127.0.0.1");
+}).listen(1337, '127.0.0.1');
 
 console.log('Server running at http://127.0.0.1:1337/');
 ```