Error when use when combined with lazy

[Ridermansb]

I received this error targetVal.concat is not a function​​ at ​​​merge​​​

const creditCardSchema = yup.object().shape({
  addressNumber: yup.lazy(val => {
    switch (typeof val) {
      case "number":
        return yup.number()
      default:
        return yup
          .string()
          .matches(/(S\/N)/i);
    }
  })
});

const paymentSchema = yup.object().shape({
  creditCard: yup.object().when("paymentMethod", {
    is: "credit_card",
    then: creditCardSchema
  }),
  paymentMethod: yup.string().required()
});

const checkoutSchema = yup.object().shape({
  payment: paymentSchema
});

checkoutSchema.validate({
    payment: {
        paymentMethod: "credit_card"
    }
}); // Throw errror targetVal.concat is not a function​​
  at ​​​merge​​​ 

You can check online ...
https://runkit.com/ridermansb/yup-error-when-lazy