Zac Efron is the "furthest thing from a prima donna", according to director Max Joseph.
The 26-year-old actor is currently filming for Max's movie, We Are Your Friends, and has been praised by the filmmaker for his professionalism and chirpy mood.
The Catfish host told MTV: "He's amazing. He is a world-class person. He's the first person to say hello to everyone and he's the furthest thing from a prima donna.
"He's extremely professional, always in a good mood and keeps things light. He loves the crew. He's a trooper, and we have a good time."
Max also revealed that the pair work well together and insists he couldn't have had anyone better than Zac to support him in the making of his first feature film.