1 files changed, 3 insertions, 2 deletions
diff --git a/nixos/modules/virtualisation/virtualbox-image.nix b/nixos/modules/virtualisation/virtualbox-image.nix
index fa580e8b42d..071edda8269 100644
--- a/nixos/modules/virtualisation/virtualbox-image.nix
+++ b/nixos/modules/virtualisation/virtualbox-image.nix
@@ -11,8 +11,9 @@ in {
   options = {
     virtualbox = {
       baseImageSize = mkOption {
-        type = types.int;
-        default = 50 * 1024;
+        type = with types; either (enum [ "auto" ]) int;
+        default = "auto";
+        example = 50 * 1024;
         description = ''
           The size of the VirtualBox base image in MiB.
         '';