diff --git a/lib/webpack/createBaseConfig.js b/lib/webpack/createBaseConfig.js
index 3a43c95d35..281be9455c 100644
--- a/lib/webpack/createBaseConfig.js
+++ b/lib/webpack/createBaseConfig.js
@@ -197,7 +197,8 @@ module.exports = function createBaseConfig ({
         .options({
           modules,
           localIdentName: `[local]_[hash:base64:8]`,
-          importLoaders: 1
+          importLoaders: 1,
+          sourceMap: !isProd
         })
 
       rule.use('postcss-loader').loader('postcss-loader').options(Object.assign({