diff --git a/content/en/docs/upgrade/upgrade-overview.md b/content/en/docs/upgrade/upgrade-overview.md
index ed4f5f64d..523a5961c 100644
--- a/content/en/docs/upgrade/upgrade-overview.md
+++ b/content/en/docs/upgrade/upgrade-overview.md
@@ -33,6 +33,6 @@ KubeSphere v3.0.0 is compatible with Kubernetes 1.15.x, 1.16.x, 1.17.x and 1.18.
 
 A brand new installer [KubeKey](https://github.com/kubesphere/kubekey) is introduced in KubeSphere v3.0.0, with which you can install or upgrade Kubernetes and KubeSphere. More details about upgrading with [KubeKey](https://github.com/kubesphere/kubekey) will be covered in the following sections.
 
-### KubeKey or ks-installer?
+## KubeKey or ks-installer?
 
 [ks-installer](https://github.com/kubesphere/ks-installer/tree/master) was the main installation tool as of KubeSphere v2. For users whose Kubernetes clusters were NOT deployed via [KubeSphere Installer](https://v2-1.docs.kubesphere.io/docs/installation/all-in-one/#step-2-download-installer-package), they should choose ks-installer to upgrade KubeSphere. For example, if your Kubernetes is hosted by cloud vendors or self provisioned, you should go for [Upgrade with ks-installer](../upgrade-with-ks-installer).