diff --git a/lib/loader.js b/lib/loader.js
index 704c17f..1f03064 100644
--- a/lib/loader.js
+++ b/lib/loader.js
@@ -51,6 +51,11 @@ module.exports = function (content) {
   // 针对 entry 的 main.js 处理 page 和 app 的入口文件和配置等
   const mpOptions = loaderUtils.getOptions(this) || {}
 
+  if (!mpOptions.fileExt) {
+    throw new Error(
+      '[mpvue-loader] need "fileExt" option in file "build/vue-loader.conf.js"，init a new project and copy the directory "build/" to this porject, or just check the "fileExt" option'
+    )
+  }
   if (mpOptions.checkMPEntry) {
     return compileMP.call(this, content, mpOptions)
   }
diff --git a/package.json b/package.json
index 4c4ce3e..9728772 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mpvue-loader",
-  "version": "1.2.0",
+  "version": "1.2.2",
   "description": "mpvue single-file component loader for Webpack",
   "main": "index.js",
   "repository": {