diff --git a/karma.conf.browsers.js b/karma.conf.browsers.js
index 5ec7f165f..d18d166b6 100644
--- a/karma.conf.browsers.js
+++ b/karma.conf.browsers.js
@@ -44,7 +44,8 @@ module.exports = (config) => {
       },
       plugins: [
         new webpack.DefinePlugin({
-          'process.env.__EX_VERSION': '\'test-runner\''
+          'process.env.__EX_VERSION': '\'test-runner\'',
+          'process.env.NODE_ENV': JSON.stringify('production')
         }),
       ],
       module: {