Liam Neeson is opening up about the time he and Ewan McGregor got reprimanded by George Lucas on the set of Star Wars.

Turns out, you’re not actually supposed to make sounds while filming a lightsaber fight scene after all.

Keep reading to find out more…

As a guest on Conan O’Brien‘s Conan O’Brien Needs a Friend podcast, Liam opened up about the funny moment as they filmed Star Wars: Episode I – The Phantom Menace.

“The first time we actually had to use the lightsaber to start a little fight…We both automatically [made the noises],” he shared, naturally.

However, they were cut off by George, who told them, “‘Let’s cut there. Boys, we can add that in later.’”

Liam and Ewan aren’t the only ones to automatically say the sounds that they’ve heard on screen while filming, many fans also do it, as did Laura Dern while filming Star Wars: The Last Jedi.

Want to watch all of the Stars Wars series and movies in order? Here’s how to do it and where to watch them, too.