diff --git a/pillar/valid_custom_grains.yaml b/pillar/valid_custom_grains.yaml
index edf435f..09e1c36 100644
--- a/pillar/valid_custom_grains.yaml
+++ b/pillar/valid_custom_grains.yaml
@@ -12,16 +12,13 @@ localized:
     default_domain: infra.opensuse.org
     default_virt_cluster: atreju
     domains: infra.opensuse.org
-    virt_cluster:
-      - bare-metal
+    virt_cluster: bare-metal
   de:
     city: nuremberg
     default_domain: infra.opensuse.org
     default_virt_cluster: atreju
     domains: infra.opensuse.org
-    virt_cluster:
-      - atreju
-      - bare-metal
+    virt_cluster: atreju
   us:
     city: provo
     default_domain: infra.opensuse.org