Barrymore, 44, opened up about her Charlie’s Angels costar, 46, at the premiere for Santa Clarita Diet season 3 to PEOPLE, calling Diaz “my bestie, my sister.”
On the Netflix show, Barrymore plays Shelia, a happily married mother who suddenly transforms into a flesh-eating zombie.
So, when asked if there was any person she’s worked with who she’d want to join her in immortality, Barrymore chose Diaz.
“Luckily, she’s in my life every day,” Barrymore said.
Since forming their bond over 18 years ago, Barrymore and Diaz have provided #friendshipgoals inspiration on several occasions.
Last year, the longtime friends shared moments from their “playdate,” which included a bare-faced, make-up free selfie — without any filter.
“Her and I are like sisters and we see each other all the time and it was just sort of where we are today,” Barrymore told PEOPLE of the selfie.
“In some ways just another day in our world, but I felt like sharing it. I love her.”
And the star maintains she wasn’t at all nervous to post the makeup-free shot. “We’d just come from a workout. We feel good. We’re not wearing any makeup and we’re just girls being ourselves. And sometimes all makeup and beauty fun aside, it’s just about the raw, honest, post workout look, you know? Just be you,” she said.
In her 2016 interview with Good Housekeeping, Barrymore said if she were ever to go to jail, Diaz would be the first person she would call.
“Not that any one of us are going to jail anytime soon,” Barrymore quickly added. “But 100 percent. She would, like, get in there and get you out.”
“If you’re looking for the best dinner-cooking partner and watching-TV-on-the-couch friend, call her,” Barrymore says. “If someone is in a medical situation, call her! She’s the most loyal, fierce, fun, cozy friend. We have incredible honesty with each other and we work hard on our lives and our friendship.”
All jokes aside, Diaz has truly proven to be that ride-or-die friend.
“Everybody pulls the wagons around, you know, our friends, whoever needs us at whatever point in time, even if it’s like something that the public doesn’t know about,” Diaz explained to Andy Cohen on his SiriusXM Radio show following the news of Barrymore and Kopelman’s divorce.
“Internally we’re all going like, ‘Okay, who needs us now?'”