diff --git a/packages/blockTools/webpack.config.js b/packages/blockTools/webpack.config.js
index b5011b39f..189b34915 100644
--- a/packages/blockTools/webpack.config.js
+++ b/packages/blockTools/webpack.config.js
@@ -3,7 +3,7 @@ const path = require('path');
 const webpack = require('webpack');
 
 module.exports = {
-  entry: './demo/index',
+  entry: './demo/index.js',
   mode: 'development',
   devServer: {
     contentBase: path.join(__dirname, 'dist'),