Serena Williams says she has reoccurring nightmares before Grand Slam finals.

“Not every time, but a lot of the times,” she said. “I dream that I leave—I'm in Australia and I leave the country to go do something in the States—and I don't make it back in time [and I get defaulted].”

Serena said that her older sister Venus has the same nightmare, too.

“Wimbledon, I had it a few times,” Serena said. “It's very disturbing. It's just the worst dream ever, the worse way to lose a match. I was like, I didn't know what I have to get and I have to fly all the way back to get it.”