type FormData = { enum: "option1" | "option2" | "option3"; }; const form = useForm({ enum: "option1" } as FormData); // ... <FormSelect form={form} name="enum"> <option value="option1">Option 1</option> <option value="option2">Option 2</option> <option value="option3">Option 3</option> {/* Next line does not show error, but option4 is invalid! */} <option value="option4">Option 4</option> </FormSelect>;