diff --git a/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx b/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx
index 10ed7bda..c7dd000e 100644
--- a/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx
+++ b/web/app/cad/craft/wizard/components/form/BooleanChioce.jsx
@@ -4,7 +4,7 @@ import {ComboBoxField} from './Fields';
 
 export default function BooleanChoice(props) {
   return <ComboBoxField {...props}>
-    <ComboBoxOption value={null}>{'<none>'}</ComboBoxOption>
+    <ComboBoxOption value=''>{'<none>'}</ComboBoxOption>
     <ComboBoxOption value={'INTERSECT'}>intersect</ComboBoxOption>
     <ComboBoxOption value={'SUBTRACT'}>subtract</ComboBoxOption>
     <ComboBoxOption value={'UNION'}>union</ComboBoxOption>