diff --git a/nixos/lib/build-vms.nix b/nixos/lib/build-vms.nix
index a97bae57d9bb..4e044deca217 100644
--- a/nixos/lib/build-vms.nix
+++ b/nixos/lib/build-vms.nix
@@ -1,6 +1,6 @@
-{ system, minimal ? false }:
+{ system, minimal ? false, config ? {} }:
 
-let pkgs = import ../.. { config = {}; inherit system; }; in
+let pkgs = import ../.. { inherit system config; }; in
 
 with pkgs.lib;
 with import ../lib/qemu-flags.nix;
diff --git a/nixos/lib/testing.nix b/nixos/lib/testing.nix
index aa1cec1ea02d..f7159634e4f1 100644
--- a/nixos/lib/testing.nix
+++ b/nixos/lib/testing.nix
@@ -1,6 +1,6 @@
-{ system, minimal ? false }:
+{ system, minimal ? false, config ? {} }:
 
-with import ./build-vms.nix { inherit system minimal; };
+with import ./build-vms.nix { inherit system minimal config; };
 with pkgs;
 
 rec {