diff --git a/modules/disko.nix b/modules/disko.nix
index 1e249a04..6faa189c 100644
--- a/modules/disko.nix
+++ b/modules/disko.nix
@@ -6,7 +6,7 @@ in
 {
   options.disko.disks = lib.mkOption {
     description = lib.mdDoc "Disk names to format.";
-    type = with lib.types; nullOr (listOf (submodule (_: {
+    type = with lib.types; listOf (submodule (_: {
       options = {
         device = lib.mkOption {
           type = lib.types.str;
@@ -46,8 +46,8 @@ in
           description = "Wether to include a zfs parition.";
         };
       };
-    })));
-    default = null;
+    }));
+    default = [ ];
   };
 
   config = {
@@ -62,10 +62,10 @@ in
           message = "Ceph requires Luks!";
         }
       ])
-      (lib.attrNames cfg.disks);
+      cfg.disks;
 
     disko = {
-      devices = lib.mkIf (cfg.disks != null) (lib.head (map
+      devices = lib.mkIf (cfg.disks != [ ]) (lib.head (map
         (disk:
           let
             diskName = if disk.name != "" then "-${disk.name}" else "";