diff --git a/docs/guide2.md b/docs/guide2.md
index df8f62d..dd113da 100644
--- a/docs/guide2.md
+++ b/docs/guide2.md
@@ -94,7 +94,7 @@ class MyProject extends Component {
       Alert.alert('提示', '刚刚更新失败了,版本被回滚.');
     }
   }
-  doUpdate = async info => {
+  doUpdate = async (info) => {
     try {
       const hash = await downloadUpdate(info);
       Alert.alert('提示', '下载完毕,是否重启应用?', [