Pagination of a SELECT of specific fields results in a RuntimeException

When paginating a DQL string which selects specific fields it results in the following error: PHP Fatal error: Uncaught exception 'RuntimeException' with message 'Not all identifier properties can be found in the ResultSetMapping: id'

NOT working: 'SELECT c.id, c.number FROM Application\Entity\Course c'
WORKING: 'SELECT c FROM Application\Entity\Course c'
WORKING: 'SELECT c, c.id, c.number FROM Application\Entity\Course c'

Setting hydration mode to scalar results makes no difference.

Gist to example code and stack trace: https://gist.github.com/d5cd6d0b0ac28e722dd7