diff --git a/lib/tests/maintainers.nix b/lib/tests/maintainers.nix
index d9d21ea74fbe..935d256d218d 100644
--- a/lib/tests/maintainers.nix
+++ b/lib/tests/maintainers.nix
@@ -1,8 +1,8 @@
 # to run these tests (and the others)
 # nix-build nixpkgs/lib/tests/release.nix
 { # The pkgs used for dependencies for the testing itself
-  pkgs
-, lib
+  pkgs ? import ../.. {}
+, lib ? pkgs.lib
 }:
 
 let
diff --git a/maintainers/maintainer-list.nix b/maintainers/maintainer-list.nix
index 5e8a93473213..689503eb7a55 100644
--- a/maintainers/maintainer-list.nix
+++ b/maintainers/maintainer-list.nix
@@ -45,7 +45,11 @@
 
     More fields may be added in the future, however, in order to comply with GDPR this file should stay as minimal as possible.
 
-    Please keep the list alphabetically sorted.
+    When editing this file:
+     * keep the list alphabetically sorted
+     * test the validity of the format with:
+         nix-build lib/tests/maintainers.nix
+
     See `./scripts/check-maintainer-github-handles.sh` for an example on how to work with this data.
 */
 {
diff --git a/maintainers/team-list.nix b/maintainers/team-list.nix
index 2ea345a652d2..1b96dce645ef 100644
--- a/maintainers/team-list.nix
+++ b/maintainers/team-list.nix
@@ -19,7 +19,10 @@
 
   More fields may be added in the future.
 
-  Please keep the list alphabetically sorted.
+  When editing this file:
+   * keep the list alphabetically sorted
+   * test the validity of the format with:
+       nix-build lib/tests/teams.nix
   */
 
 { lib }: