diff --git a/XenAdmin/Dialogs/NewDiskDialog.cs b/XenAdmin/Dialogs/NewDiskDialog.cs
index 23f3c1b10..51d53966f 100644
--- a/XenAdmin/Dialogs/NewDiskDialog.cs
+++ b/XenAdmin/Dialogs/NewDiskDialog.cs
@@ -165,6 +165,7 @@ namespace XenAdmin.Dialogs
 
             if (_vm != null)
             {
+                //note that this action alters the Device
                 var action = new CreateDiskAction(Disk, Device, _vm);
                 using (var dialog = new ActionProgressDialog(action, ProgressBarStyle.Blocks))
                     dialog.ShowDialog();
diff --git a/XenModel/Actions/VDI/CreateDiskAction.cs b/XenModel/Actions/VDI/CreateDiskAction.cs
index 2f5ca4c12..867874ae5 100644
--- a/XenModel/Actions/VDI/CreateDiskAction.cs
+++ b/XenModel/Actions/VDI/CreateDiskAction.cs
@@ -53,6 +53,8 @@ namespace XenAdmin.Actions
         {
             _device = device;
             VM = vm;
+
+            ApiMethodsToRoleCheck.AddRange("VM.get_allowed_VBD_devices", "VDI.create");
         }
 
         protected override void Run()