diff --git a/backend/Dockerfile b/backend/Dockerfile
index ec9ccb0..eb08873 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -5,7 +5,8 @@ COPY backend ./backend
 COPY alembic.ini ./
 COPY migrations ./migrations
 COPY pyproject.toml uv.lock ./
-RUN UV_DEFAULT_INDEX="https://pypi.tuna.tsinghua.edu.cn/simple/" uv sync --frozen --no-dev --no-editable --package backend
+RUN UV_DEFAULT_INDEX="https://pypi.tuna.tsinghua.edu.cn/simple/" uv lock && \
+    UV_DEFAULT_INDEX="https://pypi.tuna.tsinghua.edu.cn/simple/" uv sync --frozen --no-dev --no-editable --package backend
 
 EXPOSE 8000
 CMD ["gunicorn", "--config", "backend/gunicorn.conf.py", "backend.main:app"]