diff --git a/doc/source/configuration.rst b/doc/source/configuration.rst
index 674438daf..16ebee59d 100644
--- a/doc/source/configuration.rst
+++ b/doc/source/configuration.rst
@@ -77,3 +77,11 @@ Please note that you also need to define all the images you want to
 fetch, using the ``images`` setting. You will need to define the name
 of the image, the url where to get it, and the image type (qcow2, tar).
 As a reference, please look at the `config <http://git.openstack.org/cgit/openstack/tripleo-quickstart/tree/config/release/master-tripleo-ci.yml>`_
+
+Consuming external/custom vmlinuz and initrd for undercloud
+-----------------------------------------------------------
+
+By default, the kernel executable and initial rootfs for an undercloud VM
+are extracted from the overcloud image. In order to switch to custom
+``undercloud_custom_initrd`` and ``undercloud_custom_vmlinuz`` images,
+set the ``undercloud_use_custom_boot_images`` to True.
diff --git a/roles/libvirt/setup/undercloud/defaults/main.yml b/roles/libvirt/setup/undercloud/defaults/main.yml
index c729077ee..444cb7b5d 100644
--- a/roles/libvirt/setup/undercloud/defaults/main.yml
+++ b/roles/libvirt/setup/undercloud/defaults/main.yml
@@ -1,3 +1,6 @@
 # variable only used during gating (when compressed_gating_repo is defined)
 gating_repo_enabled: true
 
+undercloud_use_custom_boot_images: false
+undercloud_custom_vmlinuz: "{{ working_dir }}/overcloud-full.vmlinuz"
+undercloud_custom_initrd: "{{ working_dir }}/overcloud-full.initrd"
diff --git a/roles/libvirt/setup/undercloud/tasks/main.yml b/roles/libvirt/setup/undercloud/tasks/main.yml
index 978e30afd..6b35c9303 100644
--- a/roles/libvirt/setup/undercloud/tasks/main.yml
+++ b/roles/libvirt/setup/undercloud/tasks/main.yml
@@ -234,6 +234,7 @@
       '{{ working_dir }}'
     environment:
       LIBVIRT_DEFAULT_URI: "{{ libvirt_uri }}"
+    when: not undercloud_use_custom_boot_images|bool
 
   # NOTE(trown): This is a bit of a hack to get the undercloud vm
   # template to use the external kernel and initrd. We should
diff --git a/roles/libvirt/setup/undercloud/templates/undercloudvm.xml.j2 b/roles/libvirt/setup/undercloud/templates/undercloudvm.xml.j2
index 805ce84fd..e67c31b9e 100644
--- a/roles/libvirt/setup/undercloud/templates/undercloudvm.xml.j2
+++ b/roles/libvirt/setup/undercloud/templates/undercloudvm.xml.j2
@@ -6,9 +6,9 @@
     <type arch='{{ libvirt_arch }}'>hvm</type>
     <boot dev='hd'/>
     <bootmenu enable='no'/>
-{% if overcloud_as_undercloud|bool %}
-    <kernel>{{ working_dir }}/overcloud-full.vmlinuz</kernel>
-    <initrd>{{ working_dir }}/overcloud-full.initrd</initrd>
+{% if overcloud_as_undercloud|bool or undercloud_use_custom_boot_images|bool %}
+    <kernel>{{ undercloud_custom_vmlinuz }}</kernel>
+    <initrd>{{ undercloud_custom_initrd }}</initrd>
     <cmdline>console=ttyS0 root=/dev/vda</cmdline>
 {% endif %}
   </os>