diff --git a/Dockerfile b/Dockerfile
index e7016a45..e45dabfc 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -32,8 +32,9 @@ ENV LANG="C.UTF-8" \
     DOUBAN_USER_IDS=""
 WORKDIR ${WORKDIR}
 COPY . .
-RUN apt-get install musl-dev  \
-    && pip install cython  \
+RUN apt-get update \
+    && apt-get install musl-dev \
+    && pip install cython \
     && pip install -r requirements.txt \
     && python_ver=$(python3 -V | awk '{print $2}') \
     && echo "${WORKDIR}/" > /usr/local/lib/python${python_ver%.*}/site-packages/app.pth \