Leonardo DiCaprio and Brad Pitt just "clicked" on set.
The Hollywood legends starred alongside each other in Quentin Tarantino's 'Once Upon a Time in Hollywood' and Leonardo has revealed there was just an "inherent comfort" between both of them straight away.
He said: "What was very interesting about working with Brad was this strange inherent comfort and ease that we really both clicked into day one. It didn't need a lot of prep work. We talked about the script, and we instinctively knew that dynamic and relationship, and who these guys were to one another."
And Leonardo has praised Brad for being an "incredible professional".
He added to Deadline: "He's an incredible professional. Brad and I did a lot of improvising in the movie, but our relationship clicked right off the bat.
"When there is a scene that he has in his head, you hold it as a modern-day type of Shakespeare dialogue. If there's a scene that is in his head that is written a specific way, you say those lines as they're written."
Meanwhile, Leonardo previously revealed he feels "lucky" to have been acting for so long and he feels blessed to have had so many good roles.
Speaking to Entertainment Tonight at the premiere of his new movie 'Once Upon a Time in Hollywood', he said: "This is a rare sort of occurrence. Hollywood's changing in a lot of ways. This is an art film that's a throwback to different type of filmmaking. And to sit back and look at [my past self] and be able to say that I'm able to still do this and be a part of a film like this, it's pretty humbling. I feel lucky, is what I feel. I feel lucky to be an actor who's been able to work this long."