diff --git a/docs/bbr-zh.md b/docs/bbr-zh.md
index 46d46c9..5c0f55f 100644
--- a/docs/bbr-zh.md
+++ b/docs/bbr-zh.md
@@ -93,10 +93,16 @@ Amazon Linux 2提供过经过验证的新版Linux内核，并可以通过启用
    net.core.default_qdisc = fq
    net.ipv4.tcp_congestion_control = bbr
    ```
-3. 启用Google BBR
+3. 启用Google BBR   
+   首先使用 `uname -r` 检查你的服务器的内核版本。   
+   对于内核版本 >= 4.20，应用 `sysctl` 设置：
    ```bash
    sudo sysctl -p
    ```
+   对于内核版本 < 4.20，你必须重启服务器：
+   ```bash
+   sudo reboot
+   ```
 4. 检查Google BBR状态
    ```bash
    sudo sysctl net.ipv4.tcp_available_congestion_control
diff --git a/docs/bbr.md b/docs/bbr.md
index e7ddebd..39ab692 100644
--- a/docs/bbr.md
+++ b/docs/bbr.md
@@ -93,10 +93,16 @@ In this section, we will start Google BBR by modifying the configuration file.
    net.core.default_qdisc = fq
    net.ipv4.tcp_congestion_control = bbr
    ```
-3. Enable Google BBR
+3. Enable Google BBR   
+   First, check your server's kernel version using `uname -r`.   
+   For kernel versions >= 4.20, apply `sysctl` settings:
    ```bash
    sudo sysctl -p
    ```
+   For kernel versions < 4.20, you must reboot the server:
+   ```bash
+   sudo reboot
+   ```
 4. Check Google BBR status
    ```bash
    sudo sysctl net.ipv4.tcp_available_congestion_control