diff --git a/helm/dagster/schema/schema/charts/utils/utils.py b/helm/dagster/schema/schema/charts/utils/utils.py
index b84cd365bbedb..2b273e0aa4079 100644
--- a/helm/dagster/schema/schema/charts/utils/utils.py
+++ b/helm/dagster/schema/schema/charts/utils/utils.py
@@ -47,7 +47,7 @@ def schema_extra(schema, model):
                     value["anyOf"].append({"type": "null"})
 
 
-def create_definition_ref(definition: str, version: str = SupportedKubernetes.V1_18) -> str:
+def create_definition_ref(definition: str, version: str = SupportedKubernetes.V1_18.value) -> str:
     return (
         f"https://kubernetesjsonschema.dev/v{version}/_definitions.json#/definitions/{definition}"
     )