diff --git a/dockerfiles/pub-mirror/Dockerfile b/dockerfiles/pub-mirror/Dockerfile
index f3ef8cf..ca0ab26 100644
--- a/dockerfiles/pub-mirror/Dockerfile
+++ b/dockerfiles/pub-mirror/Dockerfile
@@ -1,4 +1,4 @@
-FROM google/dart:2.1.1
+FROM google/dart:2
 MAINTAINER Hui Yiqun <i@huiyiqun.me>
 
 ENV PUB_CACHE /pub-cache