Two more series of The Simpsons have been commissioned by US television network Fox, ensuring the show will be on screens until at least 2008.
The Simpsons has been running since 1989
The decision ensures the popular animated sitcom will rack up its 400th episode in the next two years.
The show, which is the longest-running prime-time entertainment series in the US, is currently in its 17th season.
The show's main cast, including Dan Castellaneta and Nancy Cartwright, are expected to stay on for the new shows.
Creator Matt Groening said last year that he had no plans to stop making the programme.
"I don't see any end in sight," he said. "I want to get to 366 [shows] so we have one for every day of the year, including leap year.
Groening said the animated hit would keep going as long as they could keep surprising viewers. "That's what you're looking for in television - surprise."
An opinion poll recently suggested that Americans knew more about The Simpsons than the US Constitution's First Amendment.
Fox has also commissioned another series of cartoon show King of the Hill. It is due to return for its 11th season in January next year.