diff --git a/usr/lib/sysctl.d/990-security-misc.conf b/usr/lib/sysctl.d/990-security-misc.conf
index 7329e77..e633df1 100644
--- a/usr/lib/sysctl.d/990-security-misc.conf
+++ b/usr/lib/sysctl.d/990-security-misc.conf
@@ -119,6 +119,7 @@ kernel.sysrq=0
 ## User namespaces aim to improve sandboxing and accessibility for unprivileged users.
 ## Unprivileged user namespaces pose substantial privilege escalation risks.
 ## Restricting may lead to breakages in numerous software packages.
+## Flatpak requires unprivileged users to create new user namespaces for sandboxing.
 ## Uncomment the second sysctl to entirely disable user namespaces.
 ## Disabling entirely will reduce compatibility with some AppArmor profiles.
 ## Disabling entirely is known to break the UPower systemd service.
@@ -127,6 +128,7 @@ kernel.sysrq=0
 ## https://madaidans-insecurities.github.io/linux.html#kernel
 ## 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
 ## https://github.com/Kicksecure/security-misc/pull/263
 ##
 ## KSPP=partial