Christmas specials tend to be a popular time to introduce a new Doctor to the Doctor Who fans around the world. This year’s Doctor Who Christmas Special will have special significance. Not only will it be the end of showrunner Steven Moffat’s tenure on the show, but it will also mark the end of Peter Capaldi’s run as The Doctor.

THR is reporting that Capaldi made the announcement to shocked listeners on BBC Radio earlier today.

“One of the greatest privileges of being Doctor Who is to see the world at its best. From our brilliant crew and creative team working for the best broadcaster on the planet, to the viewers and fans whose endless creativity, generosity and inclusiveness points to a brighter future ahead. I can’t thank everyone enough. It’s been cosmic.”