Kristen Stewart knows not every movie she has appeared in has been a hit.
In an interview with The Sunday Times, the 31-year-old actress, who plays Princess Diana in the upcoming biopic Spencer, confessed to only liking a handful of the dozens of films she has worked on throughout her career.
"It's a total crapshoot," said Stewart. "I've probably made five really good films, out of 45 or 50 films? Ones that I go, 'Wow, that person made a top-to-bottom beautiful piece of work!'"
Among her favorite films, she said, are those by director Olivier Assayas, such as Clouds of Sils Maria and Personal Shopper.
"I'd have to look at my credit list. But they are few and far between," the star continued, noting, "That doesn't mean I regret the experience [of making them]."
Stewart said she has "only regretted saying yes to a couple of films." Though it wasn't over the result, but rather that "it wasn't fun."
"The worst is when you're in the middle of something and know that not only is it probably going to be a bad movie, but we're all bracing until the end," she explained to the Times.
When asked to divulge which films made her feel that way, Stewart refused. "No! I'm not a mean person — I'm not going to call people out in public," she said.
Earlier this month, Stewart told The Daily Mail that she only had one regret about her performance in Spencer, which hits theaters on Nov. 5. "I'm not a mum yet," she said. "It's the one part of playing her that I felt disloyal about."
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
In another recent interview with Entertainment Weekly, Stewart said she's being more selective about which films she chooses to work on.
"I used to be really intentionally the opposite of precious in terms of choosing projects. For a minute there I was like, 'I'll do f------ anything!'" Stewart confessed. "And honestly, it was a good place to be for a minute."
She added, "But I think now I'm going to be a little more careful. I think I have a better nose for what's going to be fruitful for me personally, as an experience, if not necessarily what's going to thrive out in the world."