diff --git a/readme-cn.md b/readme-cn.md
index 0454b6a..a63d45b 100644
--- a/readme-cn.md
+++ b/readme-cn.md
@@ -42,7 +42,7 @@ overtls 客戶端首先與 overtls 服務端建立 TLS 連接，然後 overtls 
 如果你已經安裝了 [Rust](https://rustup.rs/)，你可以直接安裝 overtls。
 
 ```bash
-cargo install overtls
+cargo install overtls --root /usr/local/
 ```
 
 ### 預編譯二進制文件
diff --git a/readme.md b/readme.md
index 21ce26d..371fe3d 100644
--- a/readme.md
+++ b/readme.md
@@ -55,7 +55,7 @@ In summary, we need to prepare the following things
 
 If you have installed the [Rust](https://rustup.rs/), you can install overtls directly.
 ```bash
-cargo install overtls
+cargo install overtls --root /usr/local/
 ```
 
 ### Pre-compiled binary file