diff --git a/manifests/api.pp b/manifests/api.pp
index b876e2ea5..a351f789c 100644
--- a/manifests/api.pp
+++ b/manifests/api.pp
@@ -55,7 +55,7 @@
 #
 # [*instance_name_template*]
 #   (optional) Template string to be used to generate instance names
-#   Defaults to undef
+#   Defaults to $::os_service_default
 #
 # [*sync_db*]
 #   (optional) Run nova-manage db sync on api nodes after installing the package.
@@ -199,7 +199,7 @@ class nova::api(
     'nova.api.openstack.compute.limits:RateLimitingMiddleware.factory',
   $validate                                    = false,
   $validation_options                          = {},
-  $instance_name_template                      = undef,
+  $instance_name_template                      = $::os_service_default,
   $service_name                                = $::nova::params::api_service_name,
   $metadata_service_name                       = $::nova::params::api_metadata_service_name,
   $enable_proxy_headers_parsing                = $::os_service_default,
@@ -235,13 +235,13 @@ class nova::api(
   }
 
   if $instance_name_template {
-    nova_config {
-      'DEFAULT/instance_name_template': value => $instance_name_template;
-    }
+    $instance_name_template_real = $instance_name_template
   } else {
-    nova_config{
-      'DEFAULT/instance_name_template': ensure => absent;
-    }
+    warning('Using a false value for instance_name_template is deprecated. Use $::os_service_default instead.')
+    $instance_name_template_real = $::os_service_default
+  }
+  nova_config {
+    'DEFAULT/instance_name_template': value => $instance_name_template_real;
   }
 
   # enable metadata in eventlet if we do not run metadata via wsgi (nova::metadata)
diff --git a/releasenotes/notes/nova-api-instance_name_template-default-01fb4a333ff60e19.yaml b/releasenotes/notes/nova-api-instance_name_template-default-01fb4a333ff60e19.yaml
new file mode 100644
index 000000000..b418aa608
--- /dev/null
+++ b/releasenotes/notes/nova-api-instance_name_template-default-01fb4a333ff60e19.yaml
@@ -0,0 +1,8 @@
+---
+deprecations:
+  - |
+    Default value of ``nova::api::instance_name_template`` has been changed
+    from ``undef`` to ``$::os_service_default``. The parameter still accepts
+    any false value then unsets the parameter, but this behavior will be
+    changed in a future release. Use ``$::os_service_default`` if you want to
+    use the default defined in nova implementation.
diff --git a/spec/classes/nova_api_spec.rb b/spec/classes/nova_api_spec.rb
index 5bfb99a0d..488806aa4 100644
--- a/spec/classes/nova_api_spec.rb
+++ b/spec/classes/nova_api_spec.rb
@@ -43,11 +43,11 @@ describe 'nova::api' do
         is_expected.to contain_nova_config('DEFAULT/enabled_apis').with_value('osapi_compute,metadata')
       end
 
-      it { is_expected.to contain_nova_config('DEFAULT/instance_name_template').with_ensure('absent')}
 
       it { is_expected.to contain_class('nova::availability_zone') }
 
       it 'configures various stuff' do
+        is_expected.to contain_nova_config('DEFAULT/instance_name_template').with('value' => '<SERVICE DEFAULT>')
         is_expected.to contain_nova_config('wsgi/api_paste_config').with('value' => 'api-paste.ini')
         is_expected.to contain_nova_config('DEFAULT/osapi_compute_listen').with('value' => '0.0.0.0')
         is_expected.to contain_nova_config('DEFAULT/osapi_compute_listen_port').with('value' => '8774')