Claiming that he’s “had enough” of authors being asked to work for free, Philip Pullman has stepped down as patron of the Oxford Literary Festival.

The bestselling author of the His Dark Materials trilogy, announced the decision on Twitter:

Because of the Oxford Literary Festival’s attitude to paying speakers (they don’t) I can’t remain as a Patron any longer. I’ve resigned.

— Philip Pullman (@PhilipPullman) January 13, 2016

According to Nick Clark at The Independent:

Pullman has been a patron of the literary festival—one of the UK’s biggest—for the past five years, but its refusal to pay authors put him in an “awkward position” as he is also president of the Society of Authors, which campaigns for author pay at such events.

“I realised I needed to resolve the issue so I decided to step down as patron from the festival…We authors are the centre of the festival and the only reason people buy tickets in the first place. It’s only just that we should be paid. Other festivals pay and the Oxford festival pays everyone else involved from the cleaners to the people who put up the marquees.”

The Oxford Literary Festival is in its 20th year, and one of the biggest festivals in Britain. Sally Dunsmore, the festival’s director, released a statement in response, asserting that the festival was a charity, receives no public funding, and depends on sponsorships and donations for its survival. But Pullman disagrees. “There are festivals that do pay their authors and good for them. The Oxford festival seems to find it difficult and I don’t understand why.”