diff --git a/usr/lib/sysctl.d/990-security-misc.conf b/usr/lib/sysctl.d/990-security-misc.conf
index c404553..eb160ef 100644
--- a/usr/lib/sysctl.d/990-security-misc.conf
+++ b/usr/lib/sysctl.d/990-security-misc.conf
@@ -127,6 +127,7 @@ kernel.sysrq=0
 ##
 ## https://lwn.net/Articles/673597/
 ## https://madaidans-insecurities.github.io/linux.html#kernel
+## https://gitlab.com/apparmor/apparmor/-/wikis/unprivileged_userns_restriction
 ## https://github.com/a13xp0p0v/kernel-hardening-checker#questions-and-answers
 ## https://github.com/NixOS/nixpkgs/pull/84522#issuecomment-614640601
 ## https://github.com/flatpak/flatpak/wiki/User-namespace-requirements