diff --git a/nix/module-eval/bao-matrix-reader.nix b/nix/module-eval/bao-matrix-reader.nix
index e000ea65..19a0da5f 100644
--- a/nix/module-eval/bao-matrix-reader.nix
+++ b/nix/module-eval/bao-matrix-reader.nix
@@ -81,8 +81,9 @@ let
   # fixture in a state the module refuses stays evaluable and the refusal reads
   # back as data. Matched on the option name the message names rather than on
   # its prose, because the option name is the part an operator has to act on
-  # and a message that stopped naming it would be the actual defect. The same
-  # helper ./grafana.nix uses for `swarm-grafana.nix`'s own refusal.
+  # and a message that stopped naming it would be the actual defect. Same shape
+  # as ./grafana.nix's `grafanaRefusedFor`, which reads `swarm-grafana.nix`'s
+  # own refusal.
   refusedOver = m: option: lib.any (a: !a.assertion && lib.hasInfix option a.message) m.assertions;
   cases = [
     {