diff --git a/chinadns/Dockerfile b/chinadns/Dockerfile
index 58bb27b..efe987c 100644
--- a/chinadns/Dockerfile
+++ b/chinadns/Dockerfile
@@ -22,7 +22,7 @@ RUN apt-get update \
     && make \
     && make install \
     && cd .. \
-    && rm -rf ${DNS_DIR}
+    && rm -rf ${DNS_DIR} \
     && apt-get remove -y build-essential \
     && apt-get autoremove \
     && apt-get clean -y \