diff --git a/notebook/lab/webpack.conf.js b/notebook/lab/webpack.conf.js
index 1c675b8b6..98e61e012 100644
--- a/notebook/lab/webpack.conf.js
+++ b/notebook/lab/webpack.conf.js
@@ -14,6 +14,7 @@ module.exports = {
   },
   debug: true,
   bail: true,
+  devtool: 'source-map',
   module: {
     loaders: [
       { test: /\.css$/, loader: 'style-loader!css-loader' },