diff --git a/app/assets/javascripts/repo/lib/diff/diff_worker.js b/app/assets/javascripts/repo/lib/diff/diff_worker.js
index 105431442af..e74c4046330 100644
--- a/app/assets/javascripts/repo/lib/diff/diff_worker.js
+++ b/app/assets/javascripts/repo/lib/diff/diff_worker.js
@@ -1,7 +1,6 @@
 import { computeDiff } from './diff';
 
-// eslint-disable-next-line prefer-arrow-callback
-self.addEventListener('message', function diffWorker(e) {
+self.addEventListener('message', (e) => {
   const data = e.data;
 
   self.postMessage({
diff --git a/config/webpack.config.js b/config/webpack.config.js
index 78ced4c3e8c..e850f6174b1 100644
--- a/config/webpack.config.js
+++ b/config/webpack.config.js
@@ -118,7 +118,10 @@ var config = {
       },
       {
         test: /\_worker\.js$/,
-        loader: 'worker-loader',
+        use: [
+          { loader: 'worker-loader' },
+          { loader: 'babel-loader' },
+        ],
       },
       {
         test: /\.(worker(\.min)?\.js|pdf|bmpr)$/,