Robert Downey Jr is a fan of Olympus Has Fallen, Antoine Fuqua’s 2013 action movie starring Gerard Butler as a secret service agent battling terrorists that have taken over the White House.

The Iron Man actor isn’t just a fan — he’s a huge fan. So much so that he dropped Butler a fan mail thanking him for making the movie.

Speaking to Uproxx, Butler said, “Robert Downey Jr wrote me the nicest e-mail after Olympus Has Fallen. He’s like, ‘We need more of these movies.’ These are the movies, when I was in New York as a kid, and people would shout at the screen and throw things and be like, ‘No!,’ and applaud and cheer… They’re fun. There are reasons that they’ve survived. There are reasons that audiences come out. It’s like you say, it’s a throwback to the ’90s movies where you’re just like, ‘Come on!’”

Olympus Has Fallen not only introduced the zinger “Why don’t you and I play a game of f*** off. You got first” to popular culture but also spawned two sequels 2016’s London Has Fallen and 2018’s Angel Has Fallen.

In the interview, Butler said his latest, Plane, shares a similar vibe to the …Has Fallen movies. In Plane, Butler plays a — wait for it — Singapore-based commercial pilot who must protect his passengers when his aircraft crash lands in a remote part of the Philippines ruled by anti-government rebels.

“It’s a throwback where literally you’re in the energy of the group, and everybody’s either terrified or cheering you on,” Butler said of the movie, which also stars Mike Coulter (Luke Cage, The Good Wife). “The movie is it has a lot of elements in it. It’s a drama, it’s an action movie, there’s survival elements, it’s a disaster movie.”