diff --git a/nixos/yubikey.nix b/nixos/yubikey.nix
index 9ce79e2..d486e37 100644
--- a/nixos/yubikey.nix
+++ b/nixos/yubikey.nix
@@ -8,6 +8,7 @@
     enableSSHSupport = true;
   };
 
+  # FIXME Don't forget to create an authorization mapping file for your user (https://nixos.wiki/wiki/Yubikey#pam_u2f)
   security.pam.services = {
     login.u2fAuth = true;
     sudo.u2fAuth = true;