diff --git a/lib/nova b/lib/nova
index 6ce1dcc4cc..7d66b68cfb 100644
--- a/lib/nova
+++ b/lib/nova
@@ -187,6 +187,10 @@ NOVA_USE_SERVICE_TOKEN=$(trueorfalse False NOVA_USE_SERVICE_TOKEN)
 ISCSID_DEBUG=$(trueorfalse False ISCSID_DEBUG)
 ISCSID_DEBUG_LEVEL=${ISCSID_DEBUG_LEVEL:-4}
 
+# Format for notifications. Nova defaults to "unversioned" since Train.
+# Other options include "versioned" and "both".
+NOVA_NOTIFICATION_FORMAT=${NOVA_NOTIFICATION_FORMAT:-unversioned}
+
 # Functions
 # ---------
 
@@ -535,6 +539,7 @@ function create_nova_conf {
     # enable notifications, but it will allow them to function when enabled.
     iniset $NOVA_CONF oslo_messaging_notifications driver "messagingv2"
     iniset $NOVA_CONF oslo_messaging_notifications transport_url $(get_notification_url)
+    iniset $NOVA_CONF notifications notification_format "$NOVA_NOTIFICATION_FORMAT"
     iniset_rpc_backend nova $NOVA_CONF
 
     iniset $NOVA_CONF DEFAULT osapi_compute_workers "$API_WORKERS"