diff --git a/pkg/api/alerting/v2alpha1/types.go b/pkg/api/alerting/v2alpha1/types.go
index b2a895709..d1dbc1ca3 100644
--- a/pkg/api/alerting/v2alpha1/types.go
+++ b/pkg/api/alerting/v2alpha1/types.go
@@ -39,6 +39,7 @@ var (
 	ErrThanosRulerNotEnabled     = errors.New("The request operation to custom alerting rule could not be done because thanos ruler is not enabled")
 	ErrAlertingRuleNotFound      = errors.New("The alerting rule was not found")
 	ErrAlertingRuleAlreadyExists = errors.New("The alerting rule already exists")
+	ErrAlertingAPIV2NotEnabled   = errors.New("The alerting v2 API was not enabled")
 
 	ruleLabelNameMatcher = regexp.MustCompile(`[a-zA-Z_][a-zA-Z0-9_]*`)
 )
diff --git a/pkg/kapis/alerting/v2alpha1/register.go b/pkg/kapis/alerting/v2alpha1/register.go
index 3ae5f543a..3fb055d8e 100644
--- a/pkg/kapis/alerting/v2alpha1/register.go
+++ b/pkg/kapis/alerting/v2alpha1/register.go
@@ -41,10 +41,24 @@ func AddToContainer(container *restful.Container, informers informers.InformerFa
 	promResourceClient promresourcesclient.Interface, ruleClient alerting.RuleClient,
 	option *alerting.Options) error {
 
-	handler := newHandler(informers, promResourceClient, ruleClient, option)
-
 	ws := runtime.NewWebService(GroupVersion)
 
+	if informers == nil || promResourceClient == nil || ruleClient == nil || option == nil {
+		h := func(req *restful.Request, resp *restful.Response) {
+			ksapi.HandleBadRequest(resp, nil, alertingv2alpha1.ErrAlertingAPIV2NotEnabled)
+			return
+		}
+		ws.Route(ws.GET("/{path:*}").To(h).Returns(http.StatusOK, ksapi.StatusOK, nil))
+		ws.Route(ws.PUT("/{path:*}").To(h).Returns(http.StatusOK, ksapi.StatusOK, nil))
+		ws.Route(ws.POST("/{path:*}").To(h).Returns(http.StatusOK, ksapi.StatusOK, nil))
+		ws.Route(ws.DELETE("/{path:*}").To(h).Returns(http.StatusOK, ksapi.StatusOK, nil))
+		ws.Route(ws.PATCH("/{path:*}").To(h).Returns(http.StatusOK, ksapi.StatusOK, nil))
+		container.Add(ws)
+		return nil
+	}
+
+	handler := newHandler(informers, promResourceClient, ruleClient, option)
+
 	ws.Route(ws.GET("/rules").
 		To(handler.handleListCustomAlertingRules).
 		Doc("list the cluster-level custom alerting rules").