diff --git a/content/en/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm.md b/content/en/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm.md
index 64a4ce2286897..3061b9725527e 100644
--- a/content/en/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm.md
+++ b/content/en/docs/setup/production-environment/tools/kubeadm/troubleshooting-kubeadm.md
@@ -469,6 +469,7 @@ on the side of the metrics-server:
 ```
 x509: certificate signed by unknown authority
 x509: certificate is valid for IP-foo not IP-bar
+x509: cannot validate certificate for IP-foo because it doesn't contain any IP SANs
 ```
 
 See [Enabling signed kubelet serving certificates](/docs/tasks/administer-cluster/kubeadm/kubeadm-certs/#kubelet-serving-certs)