diff --git a/packages/angular-cli/models/webpack-build-production.ts b/packages/angular-cli/models/webpack-build-production.ts
index 7e0b73331d36..ad54db5c65cc 100644
--- a/packages/angular-cli/models/webpack-build-production.ts
+++ b/packages/angular-cli/models/webpack-build-production.ts
@@ -66,7 +66,7 @@ export const getWebpackProdConfigPartial = function(projectRoot: string,
       new CompressionPlugin({
           asset: '[path].gz[query]',
           algorithm: 'gzip',
-          test: /\.js$|\.html$/,
+          test: /\.js$|\.html$|\.css$/,
           threshold: 10240,
           minRatio: 0.8
       }),