Last year marked 40 years since Star Wars: The Empire Strikes Back hit theatres and the movie’s star is still taking to social media to share behind-the-scenes facts about the film. Mark Hamill, who is best known for playing Luke Skywalker, recently took to Twitter to share an original trailer for The Empire Strikes Back and had a hilarious reaction to the infamous Luke and Leia kiss. This week, one fan asked Hamill about the iconic scene between Luke and Vader, and Hamill shared a little history about the “I am your father” moment.

It’s crucial to warm up vocally prior to any demanding challenges. FYI-In that scene- NOTHING could be heard over the deafening roar of the wind-machines. I spoke my lines based on Vader’s gestures, unable to hear a word he said. Everything was dubbed in later in post-production. https://t.co/MuL78BMUOC pic.twitter.com/8bthG8xCgL