Jessica Chastain is ''proud'' of Jennifer Lawrence for speaking out on Hollywood's gender pay gap.

The 38-year-old actress has heaped praise on the Oscar-winning star after she recently bemoaned the pay gap between male and female performers.

She said: ''I'm proud of her. Sometimes when you're doing well, you're afraid to say something's wrong because then there's going to be a bunch of people out there going 'OK, well, you're a big old movie star.' But it doesn't matter.''

Jessica said it's ''completely unfair'' that actors are paid more than their female counterparts for doing the same job in the same movie.

The 'Martian' star told Variety: ''There's no excuse. There's no reason why she should be doing a film with other actors and get paid less than her male co-stars. It's completely unfair. It's not right. It's been happening for years and years and years. I think it's brave to talk about it. I think everyone should talk about it.''

Earlier this week, Jennifer admitted to being surprised by the pay gap between herself and her male co-stars in 'American Hustle', Christian Bale, Bradley Cooper, and Jeremy Renner.

She explained: ''When the Sony hack happened and I found out how much less I was being paid than the lucky people with d**ks, I didn't get mad at Sony. I got mad at myself. I failed as a negotiator because I gave up early.

''I didn't want to keep fighting over millions of dollars that, frankly, due to two franchises, I don't need. (I told you it wasn't relatable, don't hate me).''