Before Chad Stahelski and David Leitch made their directorial debut, the guys behind John Wick worked as stunt coordinators and second unit directors on films like The Matrix, The Hunger Games and The Wolverine — to name just a fraction of their credits. And while most fans are aware of their movie history, you might not know that the duo also helped Joe and Anthony Russo on Captain America: Civil War, giving them a little assistance with some of their action sequences, of course.

Stahelski previously worked stunts for Iron Man 2, but Civil War marks the first time the duo worked together on a Marvel film. And although they’ve been busy with their own directing projects, Leitch’s second unit credits include recent blockbusters like Jurassic World and Teenage Mutant Ninja Turtles.

While Leitch is in production on The Coldest City with Charlize Theron and Stahelski is working on John Wick: Chapter Two with Keanu Reeves, the pair still found time to make themselves available as second unit directors on Civil War. Speaking with Collider, Joe Russo explains how he called in a “huge favor” from his friends Stahelski and Leitch:

Just as friends we asked them if they’d come out and help us execute some of the action sequences along with Spiro Razatos, who’s generally regarded as the top guy along with Chad and Dave. We literally had an all-star team of second unit directors working on this movie with us because we cared so much about the action and the quality of the action, and we knew we had to work really hard to up our game from Winter Soldier.

Civil War is crowded with MCU superheroes (save for Thor and Hulk), so it’s easy to see how the Russos could use all the help they could get for all those big action sequences — especially from guys who have a very impressive history in stunt work and coordination.

Captain America: Civil War arrives on May 6.