diff --git a/packages/angular-cli/models/webpack-build-production.ts b/packages/angular-cli/models/webpack-build-production.ts
index 0d52a86a4678..db618f67a71a 100644
--- a/packages/angular-cli/models/webpack-build-production.ts
+++ b/packages/angular-cli/models/webpack-build-production.ts
@@ -56,7 +56,7 @@ export const getWebpackProdConfigPartial = function(projectRoot: string, appConf
         'process.env.NODE_ENV': JSON.stringify('production')
       }),
       new webpack.optimize.UglifyJsPlugin(<any>{
-        mangle: { screw_ie8 : true },
+        mangle: { screw_ie8 : true, keep_fnames: true },
         compress: { screw_ie8: true },
         sourceMap: true
       }),