diff --git a/Dockerfile b/Dockerfile
index bbcabd3..f469935 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,9 +1,6 @@
 FROM ubuntu:14.04.3
 MAINTAINER Doro Wu <fcwu.tw@gmail.com>
 
-# cache
-RUN sed -i 's#http://archive.ubuntu.com/#http://qnap.dorowu.com/#' /etc/apt/sources.list
-
 ENV DEBIAN_FRONTEND noninteractive
 ENV HOME /root