diff --git a/charts/postgres-cluster-upgrade/values.yaml b/charts/postgres-cluster-upgrade/values.yaml
index 07cb1a4..c806626 100644
--- a/charts/postgres-cluster-upgrade/values.yaml
+++ b/charts/postgres-cluster-upgrade/values.yaml
@@ -19,10 +19,10 @@ cluster:
       hugepages-2Mi: 512Mi
   storage:
     data:
-      storageClass: default
+      storageClass:
       size: 10Gi
     wal:
-      storageClass: default
+      storageClass:
       size: 2Gi
 upgrade:
   importType: microservice