diff --git a/src/http_keys.ml b/src/http_keys.ml
index 9ba359a4..58e58594 100644
--- a/src/http_keys.ml
+++ b/src/http_keys.ml
@@ -196,6 +196,7 @@ let mk_keys ~db_conn (module Sm : Secmod.S) ~last_issue_date =
   in
   let* auditors =
     (* TODO /auditors/$AUDITOR_PUB/$H_DENOM_PUB *)
+    (* does not contains auditor_keys with empty denomination_keys *)
     Pg.get_auditor_keys db_conn
   in
   let extensions = None in