diff --git a/nixos/maintainers/scripts/openstack/openstack-image-zfs.nix b/nixos/maintainers/scripts/openstack/openstack-image-zfs.nix
index 72f123b16229..ffce6deed6e0 100644
--- a/nixos/maintainers/scripts/openstack/openstack-image-zfs.nix
+++ b/nixos/maintainers/scripts/openstack/openstack-image-zfs.nix
@@ -11,10 +11,25 @@ let
   copyChannel = true;
   cfg = config.openstackImage;
   imageBootMode = if config.openstack.efi then "uefi" else "legacy-bios";
+  virtualisationOptions = import ../../../modules/virtualisation/virtualisation-options.nix;
 in
 {
   imports = [
     ../../../modules/virtualisation/openstack-config.nix
+    virtualisationOptions.diskSize
+    (lib.mkRenamedOptionModuleWith {
+      sinceRelease = 2411;
+      from = [
+        "virtualisation"
+        "openstackImage"
+        "sizeMB"
+      ];
+      to = [
+        "virtualisation"
+        "diskSize"
+      ];
+    })
+
   ] ++ (lib.optional copyChannel ../../../modules/installer/cd-dvd/channel.nix);
 
   options.openstackImage = {
@@ -30,12 +45,6 @@ in
       description = "RAM allocation for build VM";
     };
 
-    sizeMB = mkOption {
-      type = types.int;
-      default = 8192;
-      description = "The size in MB of the image";
-    };
-
     format = mkOption {
       type = types.enum [
         "raw"
@@ -61,6 +70,9 @@ in
       };
     };
 
+    virtualisation.diskSize = lib.mkDefault (8 * 1024);
+    virtualisation.diskSizeAutoSupported = false;
+
     system.build.openstackImage = import ../../../lib/make-single-disk-zfs-image.nix {
       inherit lib config;
       inherit (cfg) contents format name;
@@ -77,7 +89,7 @@ in
 
       bootSize = 1000;
       memSize = cfg.ramMB;
-      rootSize = cfg.sizeMB;
+      rootSize = config.virtualisation.diskSize;
       rootPoolProperties = {
         ashift = 12;
         autoexpand = "on";