diff --git a/Dockerfile b/Dockerfile
index 9fa23d83b..7293fa7b0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 FROM python:3.9.0-alpine
 
-RUN pip install --upgrade pip
+RUN pip install -i https://pypi.tuna.tsinghua.edu.cn/simple --upgrade pip
 RUN pip install -i https://pypi.tuna.tsinghua.edu.cn/simple mkdocs-material==9.0.13
 
 WORKDIR /app