diff --git a/data/api/server-server/definitions/unsigned_pdu_base.yaml b/data/api/server-server/definitions/unsigned_pdu_base.yaml
index 3eae5c3c..20a3e83d 100644
--- a/data/api/server-server/definitions/unsigned_pdu_base.yaml
+++ b/data/api/server-server/definitions/unsigned_pdu_base.yaml
@@ -124,7 +124,6 @@ required:
   - event_id
   - room_id
   - sender
-  - origin
   - origin_server_ts
   - type
   - content