diff --git a/packages/webpack-uni-mp-loader/lib/plugin/index-new.js b/packages/webpack-uni-mp-loader/lib/plugin/index-new.js
index 89371203c8cdaf2c6f603cbd58cb0d531a05ec75..fdbcb3490df85dfc43f3261f2a12805e5c4e55a2 100644
--- a/packages/webpack-uni-mp-loader/lib/plugin/index-new.js
+++ b/packages/webpack-uni-mp-loader/lib/plugin/index-new.js
@@ -80,12 +80,8 @@ function addMPPluginRequire (compilation) {
       const globalEnv = process.env.UNI_PLATFORM === 'mp-alipay' ? 'my' : 'wx'
       const filePath = normalizePath(path.resolve(process.env.UNI_INPUT_DIR, name))
       const uniModuleId = modules.find(module => module.resource && normalizePath(module.resource) === filePath).id
-      const newlineIndex = orignalSource.lastIndexOf('\n')
 
-      const source =
-        orignalSource.substring(0, newlineIndex) +
-        `\nmodule.exports = ${globalEnv}.__webpack_require_UNI_MP_PLUGIN__('${uniModuleId}');\n` +
-        orignalSource.substring(newlineIndex + 1)
+      const source = orignalSource + `\nmodule.exports = ${globalEnv}.__webpack_require_UNI_MP_PLUGIN__('${uniModuleId}');\n`
 
       compilation.assets[name] = {
         size () {