diff --git a/js/webpack/app.js b/js/webpack/app.js
index bcdaf9f0f..ac485554a 100644
--- a/js/webpack/app.js
+++ b/js/webpack/app.js
@@ -66,11 +66,11 @@ module.exports = {
       {
         test: /\.js$/,
         exclude: /(node_modules)/,
-        use: [ 'babel-loader' ]
+        use: [ 'happypack/loader?id=babel' ]
       },
       {
         test: /\.json$/,
-        use: [ 'json-loader' ]
+        use: ['json-loader']
       },
       {
         test: /\.ejs$/,
@@ -97,7 +97,7 @@ module.exports = {
       },
       {
         test: /\.md$/,
-        use: [ 'html-loader', 'markdown-loader' ]
+        use: ['html-loader', 'markdown-loader']
       },
       {
         test: /\.css$/,
@@ -121,7 +121,8 @@ module.exports = {
           {
             loader: 'postcss-loader',
             options: {
-              plugins: (loader) => [
+              sourceMap: true,
+              plugins: [
                 require('postcss-import'),
                 require('postcss-nested'),
                 require('postcss-simple-vars')
diff --git a/js/webpack/libraries.js b/js/webpack/libraries.js
index c0619eb41..da905cb4c 100644
--- a/js/webpack/libraries.js
+++ b/js/webpack/libraries.js
@@ -55,11 +55,11 @@ module.exports = {
       {
         test: /\.js$/,
         exclude: /node_modules/,
-        use: [ 'babel-loader' ]
+        use: [ 'happypack/loader?id=babel' ]
       },
       {
         test: /\.json$/,
-        use: [ 'json-loader' ]
+        use: ['json-loader']
       },
       {
         test: /\.html$/,
diff --git a/js/webpack/rules/es6.js b/js/webpack/rules/es6.js
index 292b64830..d6e7e58e6 100644
--- a/js/webpack/rules/es6.js
+++ b/js/webpack/rules/es6.js
@@ -17,5 +17,5 @@
 module.exports = {
   test: /\.js$/,
   include: /node_modules\/(get-own-enumerable-property-symbols|ethereumjs-tx|stringify-object)/,
-  use: [ 'babel-loader' ]
+  use: [ 'happypack/loader?id=babel' ]
 };
diff --git a/js/webpack/rules/parity.js b/js/webpack/rules/parity.js
index eb577d99a..546bbc659 100644
--- a/js/webpack/rules/parity.js
+++ b/js/webpack/rules/parity.js
@@ -17,5 +17,5 @@
 module.exports = {
   test: /\.js$/,
   include: /node_modules\/@parity\//,
-  use: [ 'babel-loader' ]
+  use: [ 'happypack/loader?id=babel' ]
 };
diff --git a/js/webpack/shared.js b/js/webpack/shared.js
index c1994c8b3..b65856966 100644
--- a/js/webpack/shared.js
+++ b/js/webpack/shared.js
@@ -18,7 +18,7 @@ const webpack = require('webpack');
 const path = require('path');
 const fs = require('fs');
 
-// const HappyPack = require('happypack');
+const HappyPack = require('happypack');
 const CircularDependencyPlugin = require('circular-dependency-plugin');
 const PackageJson = require('../package.json');
 
@@ -83,12 +83,12 @@ function getPlugins (_isProd = isProd) {
         LOGGING: JSON.stringify(!isProd),
         UI_VERSION: JSON.stringify(UI_VERSION)
       }
+    }),
+    new HappyPack({
+      id: 'babel',
+      threads: 4,
+      loaders: ['babel-loader']
     })
-    // new HappyPack({
-    //   id: 'babel',
-    //   threads: 4,
-    //   loaders: [ 'babel-loader' ]
-    // })
   ];
 
   if (_isProd) {