diff --git a/tests/intern.nix b/tests/intern.nix
index d066c24..58c4b75 100644
--- a/tests/intern.nix
+++ b/tests/intern.nix
@@ -33,6 +33,9 @@ import <nixpkgs/nixos/tests/make-test.nix> {
                   hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
               };
           };
+
+          vmailGroupName = "vmail";
+          vmailUIDStart = 5000;
         };
     };
 
@@ -49,5 +52,9 @@ import <nixpkgs/nixos/tests/make-test.nix> {
             $machine->succeed("cat /etc/shadow | grep 'user1\@example.com:\$6\$/z4n8AQl6K\$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/:1::::::'");
       };
 
+      subtest "vmail gid is set correctly", sub {
+            $machine->succeed("getent group vmail | grep 5000");
+      };
+
     '';
 }