diff --git a/modules/virtualisation/qemu-vm.nix b/modules/virtualisation/qemu-vm.nix
index c8b45f86b82..a17e167cb46 100644
--- a/modules/virtualisation/qemu-vm.nix
+++ b/modules/virtualisation/qemu-vm.nix
@@ -60,15 +60,6 @@ let
           '';
       };
       
-    virtualisation.readonlyHostFS =
-      mkOption {
-        default = true;
-        description =
-          ''
-            Whether to mount the hostfs read-only.
-          '';
-      };
-      
   };
 
   cfg = config.virtualisation;
@@ -172,7 +163,7 @@ in
       { mountPoint = "/hostfs";
         device = "//10.0.2.4/qemu";
         fsType = "cifs";
-        options = "guest,username=nobody${if config.virtualisation.readonlyHostFS then ",noperm" else ""}";
+        options = "guest,username=nobody,noperm";
         neededForBoot = true;
       }
       { mountPoint = "/nix/store";