React PropTypes - How to make a shape optional with its fields required?

I have a component that receives a badge prop (see example down below). The badge is optional, but once it is used I want it to have some required fields inside it. I've tried the following:

Component.propTypes = {
  badge: PropTypes.shape({
    src: PropTypes.string.isRequired,
    alt: PropTypes.string.isRequired,
  }),
}

It works, but I get this warning on Chrome when trying to use it without the badge:

Warning: Failed prop type: The prop badge.src is marked as required in Component, but its value is null.

What is the proper way of doing this?

Component usage example:

badge={{ src: 'usa.png', alt: 'United States' }}

badge not supplied