Los Angeles: 'The Big Bang Theory' stars have started shooting the popular sitcom's season eleven.

Kaley Cuoco, who plays Penny on the long-running show, shared a behind-the-scenes snap on Instagram to mark the beginning of the upcoming season's shoot.

The photo featured Cuoco along with Jim Parsons (Sheldon), Johnny Galecki (Leonard), Kunal Nayyar (Rajesh) and Simon Helberg (Howard) on set with their scripts.

"#bts with my @bigbangtheory_cbs brothers many moons together (sic)," she captioned the picture. Galecki then shared the same picture on his account, confirming that the filming for the new season has begun.

"Back to school. Season 11 is underway," he wrote.