diff --git a/docs/Installation.mdx b/docs/Installation.mdx
index a3f8d62..5f283a2 100644
--- a/docs/Installation.mdx
+++ b/docs/Installation.mdx
@@ -19,6 +19,12 @@ git clone https://github.com/AdisonCavani/distro-grub-themes.git
 > See [#56](https://github.com/AdisonCavani/distro-grub-themes/issues/56).
 > You should [install it manually](#manual-installation), instead.
 
+<Callout type="warning">
+  ``grub-customizer`` is not available on Ubuntu 21.10 and above.  
+  See [#56](https://github.com/AdisonCavani/distro-grub-themes/issues/56).  
+  You should [install it manually](#manual-installation), instead.
+</Callout>
+
 apt
 
 ```shell