This is it for The Big Bang Theory.

CBS' top comedy will end its run after the upcoming 12th season, airing its final episode in May 2019, it was announced Wednesday.

“We are forever grateful to our fans for their support of The Big Bang Theory during the past 12 seasons," Warner Bros. Television, CBS and Chuck Lorre Productions said in a joint statement Wednesday. "We, along with the cast, writers and crew, are extremely appreciative of the show’s success and aim to deliver a final season, and series finale, that will bringThe Big Bang Theory to an epic creative close.”

Big Bang will end its run as the longest-running multi-camera series in television history and will have aired a record-breaking 279 episodes.

“We are forever grateful to our fans for their support of The #BigBangTheory during the past twelve seasons..." pic.twitter.com/OWIHsICi6e — The Big Bang Theory (@bigbangtheory) August 22, 2018

This is a surprising turn, considering Kelly Kahl, CBS Entertainment President, revealed earlier this month at the Television Critics Association summer press tour that CBS was hopeful for a 13th season. CBS still has Big Bang prequel spinoff, Young Sheldon, on its slate.

“We don’t believe it’s the final season," Kahl said at the time of the upcoming season possibly being Big Bang's last. "We are in preliminary discussions to renew the show with the studio that produces it, Warner Bros.”

Big Bang scored a huge two-season renewal in March 2017, keeping the blockbuster comedy series on TV through 2019. It had been rumored that this could be it for the long-running series.

In March, ET's Nischelle Turner caught up with Big Bang stars at PaleyFest, where they dished on the future of the show.

"There's been no group discussion. There's been no 'come to Jesus' about this," Jim Parsons said.

Added Johnny Galecki: "We think [season] 12 will be it. Anything beyond that, we're just thinking about the very tearful wrap party we'll have."

But Kaley Cuoco seemed open to the idea of continuing with the series: "I love being a part of the show and I think it'd be really stupid to say no. There's just nothing better. Season 13 does sound kind of cool."

Created by Chuck Lorre and Bill Prady,The Big Bang Theory premiered in September 2007 and quickly became TV's top-rated and most-watched comedy. It centered on five characters living in Pasadena, California: Leonard Hofstadter (Galecki), Sheldon Cooper (Parsons), Penny (Cuoco), Howard Wolowitz (Simon Helberg) and astrophysicist Raj Koothrappali (Kunal Nayyar). As the series progressed, supporting characters like Amy Farrah Fowler (Mayim Bialik) and Bernadette Rostenkowski (Melissa Rauch) became part of the core.

Over its run, Big Bang has earned 46 Emmy nominations, including four for Outstanding Comedy Series. Parsons has won four Emmys for Outstanding Lead Actor in a Comedy Series.

The Big Bang Theory will kick off its final season on Monday, Sept. 24 at 8 p.m. ET/PT on CBS, before moving to its regular time period on Thursday, Sept. 27 at 8 p.m. ET/PT.

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