diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 959e6f085849..ba2b7755c455 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -225,7 +225,7 @@ let
     if lib.isDerivation v then
       lib.warnOnInstantiate msg v
     else if lib.isAttrs v then
-      lib.mapAttrs (lib.warn msg) v
+      lib.mapAttrs (_: lib.warn msg) v
     else if lib.isFunction v then
       arg: lib.warn msg (v arg)
     else if lib.isList v then