Worlds will collide when Young Sheldon stars Iain Armitage, Lance Barber and Montana Jordan appear in an upcoming episode of The Big Bang Theory.
CBS has confirmed the casting news but declined to shed light on whether they appear in a flashback scene.
Jim Parsons is an Executive Producer of Young Sheldon.
The episode is due to air in the US in December but Aussies will likely have to wait until 2019.
The last-ever episode is due next May.
Source: TV Line