diff --git a/package/rules/file.js b/package/rules/file.js
index 48341328c..917349260 100644
--- a/package/rules/file.js
+++ b/package/rules/file.js
@@ -2,7 +2,7 @@ const { join } = require('path')
 const { source_path: sourcePath, static_assets_extensions: fileExtensions } = require('../config')
 
 module.exports = {
-  test: new RegExp(fileExtensions.join('|'), 'i'),
+  test: new RegExp(`(${fileExtensions.join('|')})`, 'i'),
   use: [
     {
       loader: 'file-loader',