diff --git a/lib/nova b/lib/nova
index 2efe7cb9b4..8220e0f10b 100644
--- a/lib/nova
+++ b/lib/nova
@@ -150,6 +150,10 @@ NOVA_ALLOW_MOVE_TO_SAME_HOST=$(trueorfalse True NOVA_ALLOW_MOVE_TO_SAME_HOST)
 ISCSID_DEBUG=$(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
 # ---------
 
@@ -487,6 +491,7 @@ 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"