diff --git a/centos/Dockerfile b/centos/Dockerfile
index 2a33a90..b6c5649 100644
--- a/centos/Dockerfile
+++ b/centos/Dockerfile
@@ -1,4 +1,5 @@
-FROM centos:7
+ARG FROM=centos:7
+FROM ${FROM}
 
 ENV PATH=/var/lib/openstack/bin:$PATH
 ENV PROJECT=heat
diff --git a/debian/Dockerfile b/debian/Dockerfile
index 8af20f0..7512387 100644
--- a/debian/Dockerfile
+++ b/debian/Dockerfile
@@ -1,4 +1,5 @@
-FROM debian:jessie-slim
+ARG FROM=debian:jessie-slim
+FROM ${FROM}
 
 ENV PATH=/var/lib/openstack/bin:$PATH
 ENV PROJECT=heat
diff --git a/ubuntu/Dockerfile b/ubuntu/Dockerfile
index 76ef805..f46d95e 100644
--- a/ubuntu/Dockerfile
+++ b/ubuntu/Dockerfile
@@ -1,4 +1,5 @@
-FROM ubuntu:xenial
+ARG FROM=ubuntu:xenial
+FROM ${FROM}
 
 ENV PATH=/var/lib/openstack/bin:$PATH
 ENV PROJECT=heat