diff --git a/lib/k8s.nix b/lib/k8s.nix
index 8cac0b1..0cbffa3 100644
--- a/lib/k8s.nix
+++ b/lib/k8s.nix
@@ -3,7 +3,7 @@
 with lib;
 
 rec {
-  # TODO: refactor into mkOptionType
+  # TODO: refactor with mkOptionType
   mkSecretOption = {description ? "", default ? {}, allowNull ? true}: mkOption {
     inherit description;
     type = (if allowNull then types.nullOr else id) (types.submodule {
diff --git a/modules/legacy.nix b/modules/legacy.nix
index 9883507..6dc8c43 100644
--- a/modules/legacy.nix
+++ b/modules/legacy.nix
@@ -49,10 +49,12 @@ let
   prefixResources = resources: serviceName:
     mapAttrs' (name: resource: nameValuePair "${serviceName}-${name}" resource) resources;
 
+  # TODO: rewrite using mkOptionType
   defaultModuleConfigurationOptions = mapAttrs (name: moduleDefinition: mkOption {
     description = "Module default configuration for ${name} module";
     type = types.coercedTo types.unspecified (value: [value]) (types.listOf types.unspecified);
     default = [];
+    apply = filter (v: v!=[]);
   }) config.kubernetes.moduleDefinitions;
 
   getModuleDefinition = name:
@@ -101,6 +103,7 @@ in {
           description = "Module default configuration for all modules";
           type = types.coercedTo types.unspecified (value: [value]) (types.listOf types.unspecified);
           default = [];
+          apply = filter (v: v != []);
         };
       };
     };
@@ -150,7 +153,7 @@ in {
   };
 
   options.kubernetes.defaults = mkOption {
-    type = types.attrsOf (types.coercedTo types.unspecified (value: [value]) (types.listOf types.unspecified));
+    type = types.attrsOf (types.coercedTo types.attrs (value: [value]) (types.listOf types.attrs));
     description = "Legacy kubenix kubernetes defaults.";
     default = {};
   };
diff --git a/modules/testing.nix b/modules/testing.nix
index 06418d2..a245122 100644
--- a/modules/testing.nix
+++ b/modules/testing.nix
@@ -239,6 +239,7 @@ in {
       example = literalExample ''{config, ...}: {
         kubernetes.version = config.kubernetes.version;
       }'';
+      apply = filter (v: v!=[]);
       default = [];
     };