diff --git a/packages/@angular/cli/models/webpack-configs/styles.ts b/packages/@angular/cli/models/webpack-configs/styles.ts
index da05db9796c1..122be05274a3 100644
--- a/packages/@angular/cli/models/webpack-configs/styles.ts
+++ b/packages/@angular/cli/models/webpack-configs/styles.ts
@@ -177,7 +177,8 @@ export function getStylesConfig(wco: WebpackConfigOptions) {
       options: {
         // A non-function property is required to workaround a webpack option handling bug
         ident: 'postcss',
-        plugins: postcssPluginCreator
+        plugins: postcssPluginCreator,
+        sourceMap: cssSourceMap
       }
     }
   ];