1 files changed, 3 insertions, 2 deletions
diff --git a/nixos/modules/virtualisation/hyperv-image.nix b/nixos/modules/virtualisation/hyperv-image.nix
index fabc9113dfc..6845d675009 100644
--- a/nixos/modules/virtualisation/hyperv-image.nix
+++ b/nixos/modules/virtualisation/hyperv-image.nix
@@ -9,8 +9,9 @@ in {
   options = {
     hyperv = {
       baseImageSize = mkOption {
-        type = types.int;
-        default = 2048;
+        type = with types; either (enum [ "auto" ]) int;
+        default = "auto";
+        example = 2048;
         description = ''
           The size of the hyper-v base image in MiB.
         '';