diff --git a/packages/react-devtools-extensions/webpack.config.js b/packages/react-devtools-extensions/webpack.config.js
index 4592363c64a..191eabc47cb 100644
--- a/packages/react-devtools-extensions/webpack.config.js
+++ b/packages/react-devtools-extensions/webpack.config.js
@@ -285,7 +285,7 @@ module.exports = {
           {
             loader: 'css-loader',
             options: {
-              sourceMap: true,
+              sourceMap: __DEV__,
               modules: true,
               localIdentName: '[local]___[hash:base64:5]',
             },