diff --git a/deployment/flake-part.nix b/deployment/flake-part.nix
index 2d6626d..f182298 100644
--- a/deployment/flake-part.nix
+++ b/deployment/flake-part.nix
@@ -1,12 +1,7 @@
 { inputs, self, ... }:
 
 let
-  allVmIds = # 100 -- 255
-    let
-      allVmIdsFrom = x: if x > 255 then [ ] else [ x ] ++ allVmIdsFrom (x + 1);
-    in
-    allVmIdsFrom 100;
-
+  allVmIds = builtins.genList (x: 100 + x) 156; # 100 -- 255
   makeInstaller = import ./makeInstaller.nix;
 
 in
diff --git a/deployment/procolixVm.nix b/deployment/procolixVm.nix
index 5862de3..094bab3 100644
--- a/deployment/procolixVm.nix
+++ b/deployment/procolixVm.nix
@@ -16,7 +16,7 @@ in
   options = {
     procolix = {
       vmid = mkOption {
-        type = types.int;
+        type = types.ints.between 100 255;
         description = ''
           Identifier of the machine. This is a number between 100 and 255.
         '';