diff --git a/manifests/init.pp b/manifests/init.pp
index b4c4e27f..9b700f0b 100644
--- a/manifests/init.pp
+++ b/manifests/init.pp
@@ -193,6 +193,8 @@
 #   Defaults to 'v3'
 #  [*img_file*]
 #   Defaults to '/var/lib/tempest/cirros-0.4.0-x86_64-disk.img'
+#  [*img_disk_format*]
+#   Defaults to $::os_service_default
 #  [*login_url*]
 #   Defaults to undef
 #  [*dashboard_url*]
@@ -375,6 +377,7 @@ class tempest(
   $manage_tests_packages              = false,
   # scenario options
   $img_file                           = '/var/lib/tempest/cirros-0.4.0-x86_64-disk.img',
+  $img_disk_format                    = $::os_service_default,
   # designate options
   $designate_nameservers              = undef,
   # ironic options
@@ -586,6 +589,7 @@ class tempest(
     'whitebox/db_uri':                                 value => $whitebox_db_uri;
     'cli/cli_dir':                                     value => $cli_dir;
     'scenario/img_file':                               value => $img_file;
+    'scenario/img_disk_format':                        value => $img_disk_format;
     'service_broker/run_service_broker_tests':         value => $run_service_broker_tests;
     'dns/nameservers':                                 value => $designate_nameservers;
     'compute-feature-enabled/attach_encrypted_volume': value => $attach_encrypted_volume;
diff --git a/releasenotes/notes/img_disk_format-af812818355f76a8.yaml b/releasenotes/notes/img_disk_format-af812818355f76a8.yaml
new file mode 100644
index 00000000..245d2b1e
--- /dev/null
+++ b/releasenotes/notes/img_disk_format-af812818355f76a8.yaml
@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    The new ``tempest::img_disk_format`` parameter has been added.
diff --git a/spec/classes/tempest_init_spec.rb b/spec/classes/tempest_init_spec.rb
index f1cc2cef..6363f667 100644
--- a/spec/classes/tempest_init_spec.rb
+++ b/spec/classes/tempest_init_spec.rb
@@ -285,6 +285,7 @@ describe 'tempest' do
             :lock_path => '/var/lib/tempest'
           )
           is_expected.to contain_tempest_config('scenario/img_file').with(:value => '/var/lib/tempest/cirros-0.4.0-x86_64-disk.img')
+          is_expected.to contain_tempest_config('scenario/img_disk_format').with(:value => '<SERVICE DEFAULT>')
           is_expected.to contain_tempest_config('service_broker/run_service_broker_tests').with(:value => false)
           is_expected.to contain_oslo__log('tempest_config').with(
             :debug => false,