diff -r bb9a06d14857 -r 77da9c03be60 contrib/docker/centos6
--- a/contrib/docker/centos6	Fri May 30 14:14:33 2014 +0200
+++ b/contrib/docker/centos6	Sun Aug 31 13:41:09 2014 +0200
@@ -1,4 +1,4 @@
-FROM centos
+FROM centos:centos6
 RUN yum install -y gcc
 RUN yum install -y python-devel python-docutils
 RUN yum install -y make