diff --git a/Dockerfile b/Dockerfile
index a0ac053..47cf888 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM alpine
+FROM alpine:3.6
 
 ENV SERVER_ADDR     0.0.0.0
 ENV SERVER_PORT     51348
@@ -11,24 +11,20 @@ ENV TIMEOUT         300
 ENV DNS_ADDR        8.8.8.8
 ENV DNS_ADDR_2      8.8.4.4
 
+ARG BRANCH=manyuser
+ARG WORK=/root
 
-RUN apk update \
-    && apk add python \
-    libsodium \
-    unzip \
-    wget \
-  && rm -rf /var/cache/apk/*
 
+RUN apk --no-cache add python \
+    libsodium \
+    wget
 
 
-RUN wget --no-check-certificate https://github.com/shadowsocksr/shadowsocksr/archive/manyuser.zip -O /tmp/manyuser.zip \
-    && unzip -d /tmp /tmp/manyuser.zip \
-    && mv /tmp/shadowsocksr-manyuser ~/shadowsocksr \
-    && rm -rf /tmp/*
+RUN wget -qO- --no-check-certificate https://github.com/shadowsocksr/shadowsocksr/archive/$BRANCH.tar.gz | tar -xzf - -C $WORK
 
 
-WORKDIR ~/shadowsocksr/shadowsocks
+WORKDIR $WORK/shadowsocksr-$BRANCH/shadowsocks
 
 
-EXPOSE 51348
-CMD python ~/shadowsocksr/shadowsocks/server.py -p $SERVER_PORT -k $PASSWORD -m $METHOD -O $PROTOCOL -o $OBFS -G $PROTOCOLPARAM
+EXPOSE $SERVER_PORT
+CMD python server.py -p $SERVER_PORT -k $PASSWORD -m $METHOD -O $PROTOCOL -o $OBFS -G $PROTOCOLPARAM