The action man admits he was reluctant at first because he didn't want to upset his friend.

The Rocky IV star told Access Hollywood Live, "When I first heard about it I thought I don't know if wanna do this, because I'm friends with him and you don't wanna do another one of his movies, but the script was great and fun."

And he's glad he signed on as an undercover agent at a private school, opposite comedian Bill Bellamy, because the film was "a good experience", and Arnie's a fan.

"He actually liked the picture," he said.

But Dolph admits his six-year-old co-stars were a little nervous around him at first, adding, "They were a little scared in the beginning because I'm a big guy with a fake gun... but then after about a week they warmed up (to me) and realised I was just there to goof off and have a good time and drink coffee."