diff --git a/nixos/modules/services/continuous-integration/github-runner.nix b/nixos/modules/services/continuous-integration/github-runner.nix
index c3bd8f99c57..a7645e1f56e 100644
--- a/nixos/modules/services/continuous-integration/github-runner.nix
+++ b/nixos/modules/services/continuous-integration/github-runner.nix
@@ -34,6 +34,14 @@ in
Repository to add the runner to.
Changing this option triggers a new runner registration.
+
+ IMPORTANT: If your token is org-wide (not per repository), you need to
+ provide a github org link, not a single repository, so do it like this
+ https://github.com/nixos, not like this
+ https://github.com/nixos/nixpkgs.
+ Otherwise, you are going to get a 404 NotFound
+ from POST https://api.github.com/actions/runner-registration
+ in the configure script.
'';
example = "https://github.com/nixos/nixpkgs";
};