Jennifer Aniston found it hard to concentrate when filming 'Office Christmas Party' because the cast was continually corpsing.

The 47-year-old actress - who plays a grumpy CEO in the new festive movie - has revealed her co-stars were guilty of breaking character and laughing during the filming of the big group scenes - particularly Kate McKinnon, who she recalled found it hard to keep a straight face during the shoot.

Jennifer shared: ''Adorably, Kate had a really hard time keeping a straight face, so that would send all of us laughing and there were a lot of people in that room.''

The comedy also features Olivia Munn, T. J. Miller and Vanessa Bayer, and Jennifer revealed that her on-screen co-stars were constantly making her laugh on the set of the movie.

She said: ''They're all so funny, Kate obviously, Vanessa, TJ, they're all funny, it was just wonderful, everybody's cheeks hurt that day.''

The Hollywood star also recalled her favourite moment of making the festive movie.

Jennifer said: ''The car chase, being in the back seat with Kate was one of the most hilarious ... also the board room scene, I laughed a lot, these people make me laugh all the time.''