Mark Hamill has weighed in via Twitter on the news that Carrie Fisher will appear in the upcoming Star Wars, sending out a tweet calling it “bittersweet.”  He also confirmed that he and Billy Dee Williams will be in the upcoming installment.

“It’s bittersweet facing my final chapter without her-She is simply irreplaceable,” said Hamill. “I’m finding solace in the fact that she won’t BE replaced & would love the worldwide outpouring of affection from those who loved her when they heard the news.#CarrieOnForever

According to a report from Deadline, Hamill’s tweets come after Todd Fisher, the brother of the late Carrie Fisher, said he “couldn’t be more personally thrilled and happy that our Carrie will reprise her role as Princess Leia in the new and final Star Wars Episode IX using previously unreleased footage of her shot for Star Wars: The Force Awakens.”

Todd Fisher issued his statement in the wake of announcements that Carrie Fisher would appear in the upcoming film using previously filmed footage.

“As we, her family, as well as her extended family of fans around the world so believe, Carrie’s ‘Princess Leia is forever entrenched in the franchise and her indelible presence is fundamental to the film,” Todd Fisher said.  “J.J. Abrams understood Carrie’s iconic role,  and he has masterfully re-crafted this final entry to include this unused  and very last footage of Carrie ever taken, without resorting to CGI or animatronics. Our family and her fans will look forward with great anticipation for this one! Her force will forever be with us!”

Director JJ Abrams, when announcing Fisher’s presence in Episode IX, is quoted as saying: “We desperately loved Carrie Fisher. Finding a truly satisfying conclusion to the Skywalker saga without her eluded us. We were never going to recast or use a CG character. With the support and blessing from her daughter, Billie [Lourd], we have found a way to honor Carrie’s legacy and role as Leia in Episode IX by using unseen footage we shot together in Episode VII.”

Star Wars: Episode IX will begin filming August 1 at London’s Pinewood Studios, with Naomi Ackie and Richard E. Grant joining the main cast that also will include Mark Hamill, Anthony Daniels, and Billy Dee Williams as Lando Calrissian as had been tipped.

The film has a December 20, 2019, release date.