While the third season of the British drama "Sherlock" doesn’t even have an air date, co-creator Steven Moffat tells the U.K.’s Radio Times that the show’s stars have already commissioned a fourth season.

"We had to inform the BBC that Martin [Freeman] and Benedict [Cumberbatch] had commissioned a new series," Moffat said. "They signed themselves up. They both announced that they were carrying on — so that’s good. Benedict, at some red carpet event somewhere, said he was carrying on forever. Martin, at another one, said, ‘Yep, series four is happening’."

Moffat said he’s confident that the BBC will agree to a fourth season.

"But I assume that unless we’ve really screwed up ‘Sherlock’ [series three] — which we haven’t — it’s a big success and it will carry on, so long as Benedict and Martin want to do it."

The series airs on PBS in the U.S., as part of "Masterpiece."

Moffat said he wasn’t sure when the third season would air, but he "would place good money on it being at the very end or very beginning of the year."

Benedict Cumberbatch and Martin Freeman