diff --git a/lib/Common.js b/lib/Common.js
index 2dd053aab..a8eeec1ff 100644
--- a/lib/Common.js
+++ b/lib/Common.js
@@ -247,15 +247,17 @@ Common.prepareAppConf = function(opts, app) {
  * @param {string} filename
  * @return {mixed} null if not conf file, json or yaml if conf
  */
-Common.isConfigFile = function(filename) {
-  if (typeof(filename) != 'string')
+Common.isConfigFile = function (filename) {
+  if (typeof (filename) !== 'string')
     return null;
-  if (filename.indexOf('.json') != -1)
+  if (filename.indexOf('.json') !== -1)
     return 'json';
   if (filename.indexOf('.yml') > -1 || filename.indexOf('.yaml') > -1)
     return 'yaml';
-  if (filename.indexOf('.config.js') != -1)
+  if (filename.indexOf('.config.js') !== -1)
     return 'js';
+  if (filename.indexOf('.config.mjs') !== -1)
+    return 'mjs';
   return null;
 };
 
@@ -288,7 +290,7 @@ Common.parseConfig = function(confObj, filename) {
            filename.indexOf('.yaml') > -1) {
     return yamljs.parse(confObj.toString());
   }
-  else if (filename.indexOf('.config.js') > -1) {
+  else if (filename.indexOf('.config.js') > -1 || filename.indexOf('.config.mjs') > -1) {
     var confPath = require.resolve(path.resolve(filename));
     delete require.cache[confPath];
     return require(confPath);