"SURPRISE!" Ridley wrote. "It's #workoutwednesday cause I don't know if I have time to train Friday! Ran to the gym between different set ups so wore a pillowcase on my head to protect my REY HAIRSTYLE from Instagram's gaze."
It's unclear what spoilers her hairdo could give up, but better safe than sorry!
Last month, Ridley had a small scare when she feared that a skincare remedy she found while Googling might have turned her face yellow.
"I may have been slightly liberal with the turmeric," the actress joked in an Instagram video. "I have filming tomorrow ... and it's not Minions 2. It's Star Wars: Episode VIII."