Error running PHPUnit in PhpStorm

I have some PHP unit tests with in Zend Framework application I am trying to execute. If I run from the command line everything runs fine. If I run from within PhpStorm then I get the error:

PHP Fatal error:  require_once(): Failed opening required 'PHPUnit/Runner/IncludePathTestCollector.php' (include_path='C:\Users\Aaron\My Servers\php-5.2.17\PEAR') in C:\Users\Aaron\AppData\Local\Temp\phpunit_CapitalProjects_Aaron.php on line 335

I looked and that class doesn't exist in PHPUnit. Can someone tell me why it's looking for this class and/or how to resolve?

Thanks,
Aaron