diff --git a/kyaml/openapi/README.md b/kyaml/openapi/README.md
index 52e053a842..0ac38523cf 100644
--- a/kyaml/openapi/README.md
+++ b/kyaml/openapi/README.md
@@ -31,6 +31,12 @@ You may need to update the version of Kind these scripts use by changing `KIND_V
 In this directory, fetch the openapi schema, generate the
 corresponding swagger.go for the kubernetes api, and update `kubernetesapi/openapiinfo.go`:
 
+```
+make all
+```
+
+You can run the steps individually with the following commands:
+
 ```
 make kustomizationapi/swagger.go
 make kubernetesapi/swagger.go
diff --git a/kyaml/openapi/openapi.go b/kyaml/openapi/openapi.go
index 8c6422b18e..7621499c15 100644
--- a/kyaml/openapi/openapi.go
+++ b/kyaml/openapi/openapi.go
@@ -573,13 +573,12 @@ func SetSchema(openAPIField map[string]string, schema []byte, reset bool) error
 
 	// use builtin version
 	kubernetesOpenAPIVersion = version
-	if version == "" {
-		version = kubernetesapi.DefaultOpenAPI
+	if kubernetesOpenAPIVersion != "" {
+		if _, ok := kubernetesapi.OpenAPIMustAsset[kubernetesOpenAPIVersion]; !ok {
+			return fmt.Errorf("the specified OpenAPI version is not built in")
+		}
 	}
 
-	if _, ok := kubernetesapi.OpenAPIMustAsset[version]; !ok {
-		return fmt.Errorf("the specified OpenAPI version is not built in")
-	}
 	customSchema = nil
 	// if the schema is changed, initSchema should parse the new schema
 	globalSchema.schemaInit = false