diff --git a/server/lib/network.js b/server/lib/network.js
index 4dfa0ae24430d8f727f54358c6e5f6b2a10ecae8..08c574f6f5d085f05dcffcf4aeb83f09adf63388 100644
--- a/server/lib/network.js
+++ b/server/lib/network.js
@@ -1,5 +1,6 @@
-const co = require('co');
+"use strict";
 
+const co = require('co');
 
 const handleRequest = (method, uri, promiseFunc) => {
     method(uri, function(req, res) {