diff --git a/schemas/extensions.yml b/schemas/extensions.yml
index 51d8ecd..ef67628 100644
--- a/schemas/extensions.yml
+++ b/schemas/extensions.yml
@@ -86,6 +86,7 @@ nodes:
         peer: InfraFabric
         cardinality: one
         kind: Parent
+        optional: false
       - name: local_device
         peer: InfraDevice
         identifier: underlay_link_local_device