diff --git a/todo.md b/todo.md
index 18fd574..75bb95d 100644
--- a/todo.md
+++ b/todo.md
@@ -5,3 +5,7 @@
 - [ ] Reorganize modules to separate ones defining options and ones providing config
   - Move config into global, move global into root?
   - Can do the same for home manager. Put NixOS ones under `nixos`, home manager under `home`?
+
+# Issues pending fixes
+
+- [ ] Home Manager, "`optionsDocBook` is deprecated", https://github.com/nix-community/home-manager/issues/4273