diff --git a/doc/source/build-images.rst b/doc/source/build-images.rst
index 02dd378fa..d01de2c01 100644
--- a/doc/source/build-images.rst
+++ b/doc/source/build-images.rst
@@ -93,7 +93,6 @@ non-root user that was used to install the undercloud.
               # rhel-7-server-extras-rpms
               # rhel-7-server-openstack-6.0-rpms
               export REG_ACTIVATION_KEY="[activation key]"
-              export REG_HALT_UNREGISTER=""
    ::
 
           instack-build-images
diff --git a/scripts/instack-build-images b/scripts/instack-build-images
index 83f4f7245..ef7d908de 100755
--- a/scripts/instack-build-images
+++ b/scripts/instack-build-images
@@ -76,7 +76,6 @@ if [ "$NODE_DIST" = "rhel7" ]; then
         # SELinux permissive for RHEL without rhos-release
         export DIB_COMMON_ELEMENTS=selinux-permissive
     fi
-    export REG_HALT_UNREGISTER=${REG_HALT_UNREGISTER:-1}
     export DELOREAN_REPO_URL=$DELOREAN_TRUNK_REPO
 elif [ "$NODE_DIST" = "centos7" ]; then
     export DELOREAN_REPO_URL=$DELOREAN_TRUNK_REPO