Even though Star Wars: Episode IX won't be released until 2019 - and Star Wars: The Last Jedi is still in production - the movie has already started filming, with Episode IX director Colin Trevorrow having requested The Last Jedi director Rian Johnson film a scene for Episode IX making use of some of the movie's sets and cast.
“There was one little thing. It wasn’t an adjustment, it was just, ‘Could you shoot this one extra thing while you’re in this place on this day?’," Trevorrow explained to MTV's Happy Sad Confused podcast (via Entertainment Weekly). "And [Rian Johnson] did, which was great. But, it’s part of the collaborative process that exists – everyone is in communication."
The directors of the new Star Wars films have made no bones about how closely they've worked together on their films, with Johnson also having requested small changes from The Force Awakens director J..J. Abrams during that movie's production.
Star Wars: The Last Jedi is due out in theaters December 15, while Star Wars: Episode IX has a May 24, 2019 release date.