Jessica Chastain claims she suffered a nasty head injury while shooting a scene for her upcoming action thriller “The 355.”

The 44-year-old Golden Globe winner dropped the bombshell on “The Late Late Show with James Corden” Wednesday.

“I was doing a fight scene and it was on a marble floor,” Chastain told Corden of the freak accident, Yahoo Entertainment reported. “I misjudged. I had fallen and hit my head. I misjudged the distance.”

She continued, “I heard a crack. That might be why I am the way I am today.”

While she laughed about the mishap in retrospect, the “Zero Dark Thirty” star revealed that others on set “stopped and looked scared.”

“My stunt double comes up to me, she is French and doesn’t speak a lot of English, she just comes up to me and she goes, ‘I’m sorry, but I have to put it back in,’ ” Chastain described. “And I’m sitting there, I’m like, ‘Put what back in? Are my brains outside of my face? What is happening?’ And I guess it was just a bruise she was pushing back in my head.”

Despite knocking her noodle something fierce, the hardy thespian reportedly did a couple more takes before reporting to the hospital, Fox News reported.

It’s yet unclear what stunt Chastain was performing. However, the action star, who also serves as a producer on “The 355,” was reportedly forced to do many of her own stunts due to the film’s low budget.

“We made it for a fraction of the cost of what it would normally be and we are the owners of the film,” Chastain said.

Co-star Penelope Cruz, who joined Chastain on the program, said that she was “really worried” following the head-banging fiasco, which apparently wasn’t the “Tree of Life” star’s first on-set boo boo.

In another joint interview with Ellen DeGeneres, Cruz and Chastain discussed a separate incident that resulted in Cruz telling Chastain to go to the hospital again.

“We convinced you to go to the hospital, because she didn’t want to go,” Cruz claimed. “She wanted to keep going. I was like, ‘You’re going to the hospital!’ “

“The 355” stars Chastain, Cruz, Diane Kruger, Lupita Nyong’o and Fan Bingbing as spies who band together to stop a terrorist organization. The flick premieres Friday in theaters and on streaming services such as Peacock on NBC, Decider reported. It will also be available for rent on Amazon Prime, iTunes, YouTube, Google Play and more.