Harry Potter fans expecting the sorcery saga's next installment in time for summer vacation next year will have to wait a little while longer. J. K. Rowling's publishers, Bloomsbury Publishing PLC, says there will be no new Harry Potter book ready for the summer. The reason? "Basically the author hasn't finished writing it," Bloomsbury CEO Nigel Newton tells TIME, adding that the production schedule for the next three books "is still to be confirmed."

One possible reason for the delay in churning out the fifth book in the series: Two Harry Potter companion books Rowling is writing for a U.K. charity called Comic Relief. The books, "Quidditch Through the Ages" and "Fantastic Beasts and Where to Find Them", will appear under the pseudonyms of Kennilworthy Whisp and Newt Scamander on February 13. Rowling will donate net proceeds to the Harry Potter Fund at Comic Relief, U.K., a charity set up to help children in developing countries.

Still, given that book No. 4, "Harry Potter and the Goblet of Fire," checks in at a sturdy 734 pages, the delay might give everyone a chance to finish that one before springing for the next.