diff --git a/cmd/kube-apiserver/app/server.go b/cmd/kube-apiserver/app/server.go
index 62bc5c24f88..027dbfd7acc 100644
--- a/cmd/kube-apiserver/app/server.go
+++ b/cmd/kube-apiserver/app/server.go
@@ -184,13 +184,6 @@ func CreateServerChain(completedOptions completedServerRunOptions, stopCh <-chan
 		return nil, err
 	}
 
-	// otherwise go down the normal path of standing the aggregator up in front of the API server
-	// this wires up openapi
-	kubeAPIServer.GenericAPIServer.PrepareRun()
-
-	// This will wire up openapi for extension api server
-	apiExtensionsServer.GenericAPIServer.PrepareRun()
-
 	// aggregator comes last in the chain
 	aggregatorConfig, err := createAggregatorConfig(*kubeAPIServerConfig.GenericConfig, completedOptions.ServerRunOptions, kubeAPIServerConfig.ExtraConfig.VersionedInformers, serviceResolver, proxyTransport, pluginInitializer)
 	if err != nil {
diff --git a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
index 5ca0f009a8f..1e75774f45d 100644
--- a/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
+++ b/staging/src/k8s.io/apiserver/pkg/server/genericapiserver.go
@@ -205,6 +205,9 @@ type DelegationTarget interface {
 
 	// NextDelegate returns the next delegationTarget in the chain of delegations
 	NextDelegate() DelegationTarget
+
+	// PrepareRun does post API installation setup steps. It calls recursively the same function of the delegates.
+	PrepareRun() preparedGenericAPIServer
 }
 
 func (s *GenericAPIServer) UnprotectedHandler() http.Handler {
@@ -253,14 +256,19 @@ func (s emptyDelegate) ListedPaths() []string {
 func (s emptyDelegate) NextDelegate() DelegationTarget {
 	return nil
 }
+func (s emptyDelegate) PrepareRun() preparedGenericAPIServer {
+	return preparedGenericAPIServer{nil}
+}
 
 // preparedGenericAPIServer is a private wrapper that enforces a call of PrepareRun() before Run can be invoked.
 type preparedGenericAPIServer struct {
 	*GenericAPIServer
 }
 
-// PrepareRun does post API installation setup steps.
+// PrepareRun does post API installation setup steps. It calls recursively the same function of the delegates.
 func (s *GenericAPIServer) PrepareRun() preparedGenericAPIServer {
+	s.delegationTarget.PrepareRun()
+
 	if s.openAPIConfig != nil {
 		s.OpenAPIVersionedService, s.StaticOpenAPISpec = routes.OpenAPI{
 			Config: s.openAPIConfig,