Speaking at the launch of the second series, Overman acknowledged that, although the show has famous fans, he always wants to cast the best actors in his roles.
"I don't think we'd do guest parts just for the sake of it," he said. "We have a rule about casting - it's always cast the best actor rather than looking round thinking, 'Well, they've been in XYZ' or, 'They're famous'. It's served us well so far so I can't see us just sticking celebrities in."
The show's director Tom Green added: "I think it draws your attention as well. The creation of the show's so specific that if your eyes are drawn to a famous cameo just for the sake of it, it would completely break the show in a way."
Overman also revealed that the superpowers on the show are less important than the characters.
"We came up with a rule that the stories should almost work without the superpowers," he said. "And the superpowers add an additional layer on top of that. They should work as emotional teen stories with a superpower twist on top of it."
Misfits returns for a second series on November 11 at 10pm on E4.