XAMP PHP class not found

[rgwells]

I have a PHP application that uses composer to manage it's dependencies. The application works great in XAMPP so far. I just added the ramsey\Uuid\Uuid library to my application. Unfortunately, when I run the application I get a

Uncaught Error: Class "Ramsey\Uuid\Uuid" not found in ...

when the class is used. It there something I need to do to add this library to XAMPP?