diff --git a/src/index.js b/src/index.ts
similarity index 100%
rename from src/index.js
rename to src/index.ts
diff --git a/webpack.config-builder.js b/webpack.config-builder.js
index 44e7c89b68..4b5de0e0ff 100644
--- a/webpack.config-builder.js
+++ b/webpack.config-builder.js
@@ -283,7 +283,7 @@ module.exports = ({ withDevServer = true } = {}) => ({
   ...(withDevServer ? devServer() : {}),
   entry: {
     main: [
-      path.resolve(__dirname, "src/index.js"),
+      path.resolve(__dirname, "src/index.ts"),
     ],
   },
   output: {