diff --git a/dockerfiles/pub-mirror/Dockerfile b/dockerfiles/pub-mirror/Dockerfile
index 3ef5428..15f5ad8 100644
--- a/dockerfiles/pub-mirror/Dockerfile
+++ b/dockerfiles/pub-mirror/Dockerfile
@@ -1,6 +1,8 @@
 FROM google/dart:2.1.1
 MAINTAINER Hui Yiqun <i@huiyiqun.me>
 
+ENV PUB_CACHE /pub-cache
+
 RUN pub global activate pub_mirror
 
 CMD /bin/bash
diff --git a/pub.sh b/pub.sh
index bd181f8..211dda1 100755
--- a/pub.sh
+++ b/pub.sh
@@ -4,4 +4,4 @@ set -e
 BASE_URL=${MIRROR_BASE_URL:-"https://mirrors.tuna.tsinghua.edu.cn/dart-pub"}
 UPSTREAM_URL=${TUNASYNC_UPSTREAM_URL:-"https://pub.dartlang.org/api"}
 
-/root/.pub-cache/bin/pub_mirror --upstream $UPSTREAM_URL --verbose --connections 10 --concurrency 100 "$TUNASYNC_WORKING_DIR" "$BASE_URL"
+/pub-cache/bin/pub_mirror --upstream $UPSTREAM_URL --verbose --connections 10 --concurrency 100 "$TUNASYNC_WORKING_DIR" "$BASE_URL"