diff --git a/usr/lib/sysctl.d/990-security-misc.conf b/usr/lib/sysctl.d/990-security-misc.conf
index 484761e..d244a01 100644
--- a/usr/lib/sysctl.d/990-security-misc.conf
+++ b/usr/lib/sysctl.d/990-security-misc.conf
@@ -116,6 +116,7 @@ kernel.sysrq=0
 ## Restricting may lead to breakages in numerous software packages.
 ## 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 servince.
 ##
 ## https://lwn.net/Articles/673597/
 ## https://madaidans-insecurities.github.io/linux.html#kernel