David Hasselhoff worries the 'Baywatch' movie will be a ''joke''.

The 63-year-old actor - who starred in the iconic American TV series - has revealed he'd only agree to appear in the much-discussed movie alongside Zac Efron if it were to remain true to the original storyline.

Asked if he's been offered a role in the movie, David said: ''I don't really know [if I'm in it]. I don't really know if I want to be in it.''

David also said he'd previously been offered the chance to appear in a movie version of another of his TV shows, 'Knight Rider', but was unimpressed with the script.

He told ITV's 'This Morning': ''You know, I saw a 'Knight Rider' script and I hated it. The girl said, 'What did you think?' And I said, 'When it got to my part the script flew out of my hand.' I never saw it again.

''You know, if 'Night Rider' is true to 'Night Rider', I would do it. If 'Baywatch' is going to be a joke, I don't think so.

''I might do 'Baywatch' the musical or something like that. Make it something as close to what it was. They laughed at it but they still loved it. I don't want it to be a joke.''