diff --git a/docs/kubernetes/mailu/index.rst b/docs/kubernetes/mailu/index.rst
index 5032becb..5d3502a7 100644
--- a/docs/kubernetes/mailu/index.rst
+++ b/docs/kubernetes/mailu/index.rst
@@ -191,7 +191,7 @@ Happy mailing!
 
 .. _here: https://github.com/hacor/Mailu/blob/master/core/postfix/conf/main.cf#L35
 .. _cert-manager: https://github.com/jetstack/cert-manager
-.. _docs: https://cert-manager.readthedocs.io/en/latest/getting-started/2-installing.html
+.. _docs: https://cert-manager.io/docs/installation/kubernetes/#installing-with-helm
 
 Imap login fix
 ~~~~~~~~~~~~~~