diff --git a/nixos/modules/services/networking/ddclient.nix b/nixos/modules/services/networking/ddclient.nix
index 633ceaebfa4..005c57dce7c 100644
--- a/nixos/modules/services/networking/ddclient.nix
+++ b/nixos/modules/services/networking/ddclient.nix
@@ -48,7 +48,7 @@ in
         default = "";
         type = str;
         description = ''
-          Password.
+          Password. WARNING: The password becomes world readable in the Nix store.
         '';
       };