A sequel to the surprise blockbuster “Kingsman: The Secret Service” is in the works at Fox.

There was no announcement by the studio or a timetable, but there will be a followup to the R-rated comic book adaptation directed by Matthew Vaughn and starring Colin Firth, individuals with knowledge of the project told TheWrap.

It makes sense. The London-set “Kingsman: The Secret Service” crossed the $400 million mark at the global box office this weekend. It generated most of that — about $275 million — from abroad.

Also Read: How 'Kingsman: The Secret Service' Blew Away Bond, Bourne in South Korea

It became clear Fox had a hit on its hands when it opened to $41 million against “Fifty Shades of Grey” over the Presidents Day holiday weekend in the U.S.

Samuel Jackson, Michael Caine and Taron Egerton co-starred in “Kingsman,” which had an $80 million production budget. Vaughn also co-wrote with Jane Goldman and produced the film, which was based on the comic book “The Secret Service” created by Mark Millar and Dave Gibbons.

The London-based Vaughn, who directed 2011’s “X-Men: First Class” for Fox and “Kick-Ass,” has a busy schedule.

Also Read: Matthew Vaughn in Talks to Direct 'Flash Gordon' Remake

He’s in line to direct “Flash Gordon,’ a Fox reboot of the 1930s comic book series that led to a series of Buster Crabbe serials and a 1980 movie. Vaughn is also working on a film for Fox about Eddie “The Eagle” Edwards, who became the U.K.’s first Olympic ski jumper in 1988. And Vaughn is developing another adaptation of a comic book for Fox, “The Golden Age,” about superheroes in a retirement home.

He and Valerie Van Galder are producing “Ghostgirl,” based on the best-selling young adult novel series by Tonya Hurley, about a high school senior who feels invisible and suddenly really is, when she dies.