Carey Mulligan made a promise to herself as a teenager that ''one day'' she'd get to work with Leonardo Dicaprio.

The 29-year-old actress starred alongside the 40-year-old actor in 'The Great Gatsby' in 2013 and has admitted she had always dreamed of working with the hunky star and found him incredibly professional and helpful.

Asked if he was one of her girlhood crushes, she explained: ''In that I promised myself one day I would work with him. He wants everyone to be as good as they can be. Even in the first audition, we were doing a scene where Daisy freaks out and drops a lighter. During that he started improvising as Gatsby, off camera, just to help me. That's the kind of guy he is.''

The 'Far from the Madding Crowd' star - who is married to Marcus Mumford - went on to confess she thought she'd blown her audition for Baz Luhrman's film adaptation of F. Scott Fitzgerald's novel of the same name when the director failed to get back to her for over two weeks.

Speaking about the moment she learned she'd got the part, she told Britain's HELLO! magazine: ''I wish I could say I was cool about it. It was about three weeks after the last audition and I'd given up hope when Baz rang and gave me the good news. I thanked him for about 10 minutes. I wouldn't let him talk, so many tears!''