diff --git a/cmd/adapter/adapter.go b/cmd/adapter/adapter.go
index 7407dcdb..ed14e4f6 100644
--- a/cmd/adapter/adapter.go
+++ b/cmd/adapter/adapter.go
@@ -29,7 +29,9 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	openapinamer "k8s.io/apiserver/pkg/endpoints/openapi"
+	"k8s.io/apiserver/pkg/features"
 	genericapiserver "k8s.io/apiserver/pkg/server"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/client-go/metadata"
 	"k8s.io/client-go/metadata/metadatainformer"
 	"k8s.io/client-go/rest"
@@ -292,15 +294,23 @@ func main() {
 	}
 	cmd.Name = "prometheus-metrics-adapter"
 
-	cmd.OpenAPIConfig = genericapiserver.DefaultOpenAPIConfig(generatedopenapi.GetOpenAPIDefinitions, openapinamer.NewDefinitionNamer(api.Scheme, customexternalmetrics.Scheme))
-	cmd.OpenAPIConfig.Info.Title = "prometheus-metrics-adapter"
-	cmd.OpenAPIConfig.Info.Version = "1.0.0"
-
 	cmd.addFlags()
 	if err := cmd.Flags().Parse(os.Args); err != nil {
 		klog.Fatalf("unable to parse flags: %v", err)
 	}
 
+	if cmd.OpenAPIConfig == nil {
+		cmd.OpenAPIConfig = genericapiserver.DefaultOpenAPIConfig(generatedopenapi.GetOpenAPIDefinitions, openapinamer.NewDefinitionNamer(api.Scheme, customexternalmetrics.Scheme))
+		cmd.OpenAPIConfig.Info.Title = "prometheus-metrics-adapter"
+		cmd.OpenAPIConfig.Info.Version = "1.0.0"
+	}
+
+	if cmd.OpenAPIV3Config == nil && utilfeature.DefaultFeatureGate.Enabled(features.OpenAPIV3) {
+		cmd.OpenAPIV3Config = genericapiserver.DefaultOpenAPIV3Config(generatedopenapi.GetOpenAPIDefinitions, openapinamer.NewDefinitionNamer(api.Scheme, customexternalmetrics.Scheme))
+		cmd.OpenAPIV3Config.Info.Title = "prometheus-metrics-adapter"
+		cmd.OpenAPIV3Config.Info.Version = "1.0.0"
+	}
+
 	// if --metrics-max-age is not set, make it equal to --metrics-relist-interval
 	if cmd.MetricsMaxAge == 0*time.Second {
 		cmd.MetricsMaxAge = cmd.MetricsRelistInterval