diff --git a/cluster/threat-actor.json b/cluster/threat-actor.json
index 1964e8c9..3464d98a 100644
--- a/cluster/threat-actor.json
+++ b/cluster/threat-actor.json
@@ -1,5 +1,6 @@
 {
    "name" : "threat actor",
    "description": "threat actor cluster",
-   "elementOneOf": ["apt-groups", "threat-actor-intended-effect-vocabulary"]
+   "version": 1,
+   "elementOneOf": ["apt-groups", "threat-actor-intended-effect-vocabulary", "threat-actor-motivation-vocabulary"]
 }