diff --git a/install-nvidia-smi.md b/install-nvidia-smi.md
index 7a71543..c08d110 100644
--- a/install-nvidia-smi.md
+++ b/install-nvidia-smi.md
@@ -10,6 +10,10 @@ sudo apt-get install -y cuda-drivers
 nvidia-smi
 ```
 
+```
+sudo grep -r "mirrors.tuna.tsinghua.edu.cn" /etc /usr 2>/dev/null
+```
+
 ```shell
 nvcc -V
 ```