Simon Pegg is terrified watching Tom Cruise carry out stunts.

The 50-year-old actor can't help feel a sense of dread when Tom – who is famous for completing his own stunt scenes – films for the 'Mission: Impossible' series.

In an interview with Conan O'Brien, Simon – who plays Benji Dunn in the action franchise – said: "When you watch the movie and you see him do those stunts, and it's nail-biting and there's a real sense of genuine kind of peril because you know that it's him.

"But you know he survived because he was on 'Good Morning America' that morning and he did some press. When we watch him do it, we have no idea if he's going to survive. So he takes a ride off a cliff, and everybody's just waiting for, 'Good canopy, good canopy, anybody?' It's terrifying."

Pegg also opened up on the preparation that Cruise, who portrays Ethan Hunt in the franchise, has done for his stunts on the upcoming 'Mission: Impossible 7'.

The 'Shaun of the Dead' star explained: "He loves it.

"He puts in a lot of work, he trains rigorously. He literally will become the best at, you tell him something and he'll just become the best at it. He'll take as many hours as it takes, but he won't do the stunt until he knows (it's safe). The prep that went into the big stunts for this film are insane."

Simon previously revealed that he would love to go the space with the 'Top Gun' star.

Cruise has teamed up with Elon Musk's SpaceX and NASA for a project that would become the first narrative movie to be filmed in outer space and Simon wants to join him in orbit.

He said: "I'd love to go into space, it would be amazing! But you know, you have to also think about your family and safety and stuff.

"Tom never does anything recklessly and all of his stunts are meticulously designed, rehearsed and trained for. If he does it, it will be really safe. So, I don't know, you never know."