diff --git a/nova/notifications/objects/instance.py b/nova/notifications/objects/instance.py
index 30949b3ba24a..3daf864b6849 100644
--- a/nova/notifications/objects/instance.py
+++ b/nova/notifications/objects/instance.py
@@ -236,7 +236,7 @@ class InstanceCreatePayload(InstanceActionPayload):
         self.tags = [instance_tag.tag
                      for instance_tag in instance.tags]
         self.trusted_image_certificates = None
-        if instance.get("trusted_certs", None):
+        if instance.trusted_certs:
             self.trusted_image_certificates = instance.trusted_certs.ids
 
 
@@ -322,14 +322,14 @@ class InstanceActionRebuildPayload(InstanceActionPayload):
             nullable=True)
     }
 
-    def __init__(self, context, instance, fault, bdms):
+    def __init__(self, context, instance, fault, bdms=None):
         super(InstanceActionRebuildPayload, self).__init__(
                 context=context,
                 instance=instance,
                 fault=fault,
                 bdms=bdms)
         self.trusted_image_certificates = None
-        if instance.get("trusted_certs", None):
+        if instance.trusted_certs:
             self.trusted_image_certificates = instance.trusted_certs.ids
 
 
diff --git a/releasenotes/notes/trusted-certs-microversion-589b75f0180d4d51.yaml b/releasenotes/notes/trusted-certs-microversion-589b75f0180d4d51.yaml
index f37c539826f6..92dda25b665b 100644
--- a/releasenotes/notes/trusted-certs-microversion-589b75f0180d4d51.yaml
+++ b/releasenotes/notes/trusted-certs-microversion-589b75f0180d4d51.yaml
@@ -30,17 +30,17 @@ features:
     * ``POST /servers/{server_id}/action (rebuild)``
 
     The payload of the ``instance.create.start`` and ``instance.create.end``
-    and ``instance.create.error`` notifications have been extended with the
-    ``trusted_image_certificates`` field that contains the list of trusted
-    certificate IDs used when the instance is created.
+    and ``instance.create.error`` versioned notifications have been extended
+    with the ``trusted_image_certificates`` field that contains the list of
+    trusted certificate IDs used when the instance is created.
 
     The payload of the ``instance.rebuild.start`` and ``instance.rebuild.end``
-    and ``instance.rebuild.error`` notifications have been extended with the
-    ``trusted_image_certificates`` field that contains the list of trusted
-    certificate IDs used when the instance is rebuilt. This change also causes
-    the type of the payload object to change from ``InstanceActionPayload``
-    version 1.6 to ``InstanceActionRebuildPayload`` version 1.7. See the
-    `notification dev reference`_ for the sample file of
+    and ``instance.rebuild.error`` versioned notifications have been extended
+    with the ``trusted_image_certificates`` field that contains the list of
+    trusted certificate IDs used when the instance is rebuilt. This change also
+    causes the type of the payload object to change from
+    ``InstanceActionPayload`` version 1.6 to ``InstanceActionRebuildPayload``
+    version 1.7. See the `notification dev reference`_ for the sample file of
     ``instance.rebuild.start`` as an example.
 
     .. _notification dev reference: https://docs.openstack.org/developer/nova/notifications.html
\ No newline at end of file