Carrie Fisher told an audience of Star Wars fans that she gave her on-screen son Adam Driver a spanking when she met him for The Force Awakens.
Fisher, 59, played Princess Leia in the original movies. As General Leia in 2015's sequel, she has a grown-up son, Kylo Ren, played by Driver.
Unfortunately, Kylo turned to the dark side, following in his grandfather Darth Vader's footsteps.
Speaking at Star Wars Celebration in London, Fisher said Leia had been through a difficult time with her son and her partner, Han Solo (Harrison Ford).
She explained: "Han and I have a very, very volatile relationship, obviously, which leads to space divorce as you know. No, I don't think we are divorced, we're just estranged.
"Which is very rough, and we had a child, who turned out to be Hitler. Naughty Hitler. Well, you'd feel bad too if your son did all that, wouldn't you?
"But I did spank Adam when I first met him, so that felt good."
She added: "He's very tall so I don't think he was scared."
The actress added that she had enjoyed reuniting with Ford, 74 - but her favourite part of filming The Force Awakens was getting to shout at him again.
She said: "There was a little bit where I kind of yell at him. Not really yell, but it's fun to go back to the old days when we treated each other badly. That's always my favourite part, is treating Harrison badly."
Fisher told host Warwick Davis, who played an Ewok, that she was inseparable from her character.
"I'm always Princess Leia," she said, adding: "I am Leia and Leia is me."