diff --git a/nixos/tests/postfix-tlspol.nix b/nixos/tests/postfix-tlspol.nix
index d4f9f69d9bb5..d1af9877adb3 100644
--- a/nixos/tests/postfix-tlspol.nix
+++ b/nixos/tests/postfix-tlspol.nix
@@ -7,7 +7,7 @@
 
   meta.maintainers = with lib.maintainers; [ hexa ];
 
-  nodes.machine = {
+  containers.machine = {
     services.postfix.enable = true;
     services.postfix-tlspol.enable = true;