diff --git a/app/components/form/fields/ListboxField.tsx b/app/components/form/fields/ListboxField.tsx
index 3cf0f72553..dbcdaf3839 100644
--- a/app/components/form/fields/ListboxField.tsx
+++ b/app/components/form/fields/ListboxField.tsx
@@ -24,7 +24,11 @@ export function ListboxField({
   description,
   helpText,
 }: ListboxFieldProps) {
-  const [, { value }, { setValue }] = useField({ name })
+  type ItemValue = typeof items[number]['value'] | undefined
+  const [, { value }, { setValue }] = useField<ItemValue>({
+    name,
+    validate: (v) => (required && !v ? `${name} is required` : undefined),
+  })
   return (
     <div className="max-w-lg">
       <div className="mb-2">
diff --git a/app/forms/network-interface-create.tsx b/app/forms/network-interface-create.tsx
index b1dc84aa42..ef4ec5b686 100644
--- a/app/forms/network-interface-create.tsx
+++ b/app/forms/network-interface-create.tsx
@@ -88,7 +88,7 @@ export default function CreateNetworkInterfaceSideModalForm({
         name="vpcName"
         label="VPC"
         items={vpcs.map(({ name }) => ({ label: name, value: name }))}
-        // required
+        required
       />
       <SubnetListbox
         id="nic-subnet"
@@ -96,7 +96,7 @@ export default function CreateNetworkInterfaceSideModalForm({
         label="Subnet"
         vpcNameField="vpcName"
         vpcs={vpcs}
-        // required
+        required
       />
       <TextField id="nic-ip" name="ip" label="IP Address" />
     </SideModalForm>