diff --git a/swh/web/assets/config/webpack.config.production.js b/swh/web/assets/config/webpack.config.production.js
index 1993c8d1..f8dc76de 100644
--- a/swh/web/assets/config/webpack.config.production.js
+++ b/swh/web/assets/config/webpack.config.production.js
@@ -1,45 +1,46 @@
 /**
  * Copyright (C) 2018-2019  The Software Heritage developers
  * See the AUTHORS file at the top-level directory of this distribution
  * License: GNU Affero General Public License version 3, or any later version
  * See top-level LICENSE file for more information
  */
 
 // webpack configuration for compiling static assets in production mode
 
 // import required webpack plugins
 const TerserPlugin = require('terser-webpack-plugin');
 const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
 
 // import webpack development configuration
 var webpackProdConfig = require('./webpack.config.development');
 
 // override mode to production
 webpackProdConfig.mode = 'production';
 
 // configure minimizer for js and css assets
 webpackProdConfig.optimization.minimizer = [
   // use terser for minimizing js and generate source map files
   new TerserPlugin({
     cache: true,
     parallel: true,
     sourceMap: true
   }),
   // use cssnano for minimizing css and generate source map files
   new OptimizeCSSAssetsPlugin({
     cssProcessorOptions: {
       map: {
-        inline: false
+        inline: false,
+        annotation: true
       },
       minifyFontValues: false,
       discardUnused: false,
       zindex: false
     }
   })
 ];
 
 // prevent modules concatenation for generating weblabels
 webpackProdConfig.optimization.concatenateModules = false;
 
 // webpack production configuration
 module.exports = webpackProdConfig;