diff --git a/docker/alpine/README.md b/docker/alpine/README.md
index 4e174174..cb2d852f 100644
--- a/docker/alpine/README.md
+++ b/docker/alpine/README.md
@@ -18,7 +18,7 @@ $ docker --version
 ## Build docker image
 
 ```bash
-$ curl -sSL https://github.com/shadowsocks/shadowsocks-libev/raw/master/docker/alpine/Dockerfile | docker build -t shadowsocks-libev .
+$ curl -sSL https://github.com/shadowsocks/shadowsocks-libev/raw/master/docker/alpine/Dockerfile | docker build -t shadowsocks-libev -
 $ docker images
 ```