diff --git a/manifests/compute.pp b/manifests/compute.pp
index 2aee5bd28..975fefc50 100644
--- a/manifests/compute.pp
+++ b/manifests/compute.pp
@@ -69,6 +69,10 @@
 #   Time period must be hour, day, month or year
 #   Defaults to 'month'
 #
+#  [*force_raw_images*]
+#   (optional) Force backing images to raw format.
+#   Defaults to true
+#
 class nova::compute (
   $enabled                       = false,
   $manage_service                = true,
@@ -85,7 +89,8 @@ class nova::compute (
   $neutron_enabled               = true,
   $network_device_mtu            = undef,
   $instance_usage_audit          = false,
-  $instance_usage_audit_period   = 'month'
+  $instance_usage_audit_period   = 'month',
+  $force_raw_images              = true,
 ) {
 
   include nova::params
@@ -159,4 +164,8 @@ class nova::compute (
   package { 'pm-utils':
     ensure => present,
   }
+
+  nova_config {
+    'DEFAULT/force_raw_images': value => $force_raw_images;
+  }
 }
diff --git a/spec/classes/nova_compute_spec.rb b/spec/classes/nova_compute_spec.rb
index c70202724..c1fc79d57 100644
--- a/spec/classes/nova_compute_spec.rb
+++ b/spec/classes/nova_compute_spec.rb
@@ -33,6 +33,8 @@ describe 'nova::compute' do
       it { should contain_package('pm-utils').with(
         :ensure => 'present'
       ) }
+
+      it { should contain_nova_config('DEFAULT/force_raw_images').with(:value => true) }
     end
 
     context 'with overridden parameters' do
@@ -40,7 +42,8 @@ describe 'nova::compute' do
         { :enabled            => true,
           :ensure_package     => '2012.1-2',
           :vncproxy_host      => '127.0.0.1',
-          :network_device_mtu => 9999 }
+          :network_device_mtu => 9999,
+          :force_raw_images   => false }
       end
 
       it 'installs nova-compute package and service' do
@@ -67,6 +70,8 @@ describe 'nova::compute' do
           'http://127.0.0.1:6080/vnc_auto.html'
         )
       end
+
+      it { should contain_nova_config('DEFAULT/force_raw_images').with(:value => false) }
     end
 
     context 'with neutron_enabled set to false' do