diff --git a/README.md b/README.md
index 8a092327..3628da56 100644
--- a/README.md
+++ b/README.md
@@ -98,7 +98,7 @@ offline mode.
 Base images
 -----------
 
-These are cached by the standard elements - ubuntu, fedora.
+These are cached by the standard elements - fedora, redhat, ubuntu.
 
 source-repositories
 -------------------
@@ -140,11 +140,13 @@ VM image with partition table and installed grub boot sector. The mellanox
 element adds support for mellanox infiniband hardware to both the deploy
 ramdisk and the built images.
 
-Images start as a base ubuntu cloud image. Other distributions may be added in
-future, the infrastructure deliberately makes few assumptions about the exact
-operating system is use. The base image has opensshd running (a new key
-generated on first boot) and accepts use keys via the cloud metadata service,
-loading them into the 'ubuntu' user.
+Images must specify a base distribution image element. Currently base
+distribution elements exist for fedora, rhel, and ubuntu.  Other
+distributions may be added in future, the infrastructure deliberately
+makes few assumptions about the exact operating system in use.
+The base image has opensshd running (a new key generated on first boot)
+and accepts keys via the cloud metadata service, loading them into the
+distribution specific default user account.
 
 The goal of a built image is to have any global configuration ready to roll,
 but nothing that ties it to a specific cloud instance: images should be able to
@@ -208,8 +210,8 @@ part of the process you need to customise:
 
 * root.d: Create or adapt the initial root filesystem content. This is where
   alternative distribution support is added, or customisations such as
-  building on an existing image. If no element configures a root, the ubuntu
-  element will be automatically invoked to obtain an Ubuntu image.
+  building on an existing image. 
+
   Runs outside the chroot on the host environment.
   
   Only one element can use this at a time unless particular care is taken not
diff --git a/bin/disk-image-create b/bin/disk-image-create
index 4ec0d6f8..581c0e2d 100755
--- a/bin/disk-image-create
+++ b/bin/disk-image-create
@@ -63,6 +63,8 @@ function show_options () {
     echo
     echo "ELEMENTS_PATH will allow you to specify multiple locations for the elements."
     echo
+    echo "NOTE: At least one distribution root element must be specified."
+    echo
     echo "Examples:"
     echo "    ${SCRIPTNAME} -a amd64 -o ubuntu-amd64 vm ubuntu"
     echo "    export ELEMENTS_PATH=~/source/tripleo-image-elements/elements"
diff --git a/lib/common-functions b/lib/common-functions
index 712f2c87..f00e06ec 100644
--- a/lib/common-functions
+++ b/lib/common-functions
@@ -242,14 +242,10 @@ function create_base () {
     # Copy data in to the root.
     TARGET_ROOT=$TMP_MOUNT_PATH run_d root
     if [ -z "$(ls $TMP_MOUNT_PATH | grep -v '^lost+found\|tmp$')" ] ; then
-        # Nothing copied in, use Ubuntu.  Note the test above allows
-        # root.d elements to put things in /tmp, and still have the
-        # automatic Ubuntu behaviour.
-        echo "Adding ubuntu element as / had no contents"
-        IMAGE_ELEMENT=$($SCRIPT_HOME/element-info --expand-dependencies $IMAGE_ELEMENT ubuntu)
-        generate_hooks
-        echo "Now building: $IMAGE_ELEMENT"
-        TARGET_ROOT=$TMP_MOUNT_PATH run_d root
+        # No root element copied in. Note the test above allows
+        # root.d elements to put things in /tmp
+        echo "Please include at least one distribution root element."
+        exit 1
     fi
 
     # Configure Image