diff --git a/default.nix b/default.nix
index 788119f..db604ee 100644
--- a/default.nix
+++ b/default.nix
@@ -1,4 +1,4 @@
-{ pkgs ? import <nixpkgs> {}, lib ? pkgs.lib }:
+{ pkgs ? import <nixpkgs> {}, nixosPath ? toString <nixpkgs/nixos>, lib ? pkgs.lib }:
 
 with lib;
 
@@ -7,7 +7,7 @@ let
   lib' = lib.extend (lib: self: import ./lib/extra.nix { inherit lib pkgs; });
 
   defaultSpecialArgs = {
-    inherit kubenix;
+    inherit kubenix nixosPath;
   };
 
   # evalModules with same interface as lib.evalModules and kubenix as
diff --git a/examples/nginx-deployment/image.nix b/examples/nginx-deployment/image.nix
index 8fb0fc3..347d6d7 100644
--- a/examples/nginx-deployment/image.nix
+++ b/examples/nginx-deployment/image.nix
@@ -4,7 +4,7 @@ dockerTools.buildLayeredImage {
   name = "nginx";
   contents = [ nginx ];
   extraCommands = ''
-    mkdir etc
+    mkdir -p etc
     chmod u+w etc
     echo "nginx:x:1000:1000::/:" > etc/passwd
     echo "nginx:x:1000:nginx" > etc/group
diff --git a/modules/k8s.nix b/modules/k8s.nix
index 61f46e0..e74ce81 100644
--- a/modules/k8s.nix
+++ b/modules/k8s.nix
@@ -235,6 +235,7 @@ in {
 
     resources = mkOption {
       description = "Alias for `config.kubernetes.api.resources` options";
+      default = {};
     };
 
     customTypes = mkOption {
diff --git a/modules/test.nix b/modules/test.nix
index 91bdacd..449520b 100644
--- a/modules/test.nix
+++ b/modules/test.nix
@@ -49,6 +49,7 @@ in {
     extraCheckInputs = mkOption {
       description = "Extra check inputs";
       type = types.listOf types.package;
+      default = [];
     };
 
     testScript = mkOption {