Talk about twinning!
"Who's who," Demi, 56, captioned the snap.
In the image, both women don black-rimmed eyeglasses that match their long dark hair. Courteney, 55, rocks an all black ensemble, while Demi sports denim overalls with a black turtleneck underneath.
"Haha! I'll have to send you a pic that I was even confused by," Courteney commented.
The image was initially taken in 2016 at the Superga Xo Jennifer Meyer Collection launch at the Chateau Marmont in Los Angeles.
Fans loved Demi's post, as many noted the similarities in the women's appearances.
The social media post comes as Demi is set to release her new memoir "Inside Out," in which she addresses everything from to her sexual relationship with ex-husband Ashton Kutcher, to a miscarriage she suffered in the early 2000s.
Courteney, meanwhile, has been celebrating the 25th anniversary of the beloved sitcom "Friends."
On Thursday, the "Cougar Town" star posted an image of the "Friends" cast.
"Celebrating a Thursday night 25 years ago. Thank you to all of our loyal fans across the world," she wrote alongside the image. "You've certainly been there for us!"