Creating a assignment_uploadsingle activity ends in a fatal error

1. Enable Assignment 2.2
2. Create a new activity Upload a single file
3. File in the form and click 'Submit and display'

Expected

• The activity is created and you're redirected to the activity

Actual

• The following fatal error occurs:

  Fatal error: Cannot redeclare class assignment_uploadsingle in /Users/fmc/code/php/repositories/i26/moodle/mod/assignment/type/uploadsingle/assignment.class.php on line 443

This worked fine on 2.4 and 2.5