Millie Bobby Brown and Noah Schnapp have a guaranteed way of ensuring their friendship lasts.

The “Stranger Things” stars revealed during an interview with MTV News that they are each other’s marital fallback plans.

“We said if we’re not married by 40, we’ll get married together,” she explained. “Because we’d be good roomies.”

Schnapp agreed and Brown added it would be “completely platonically.”

Their union would not see the two becoming parents, however.

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“No kids, though, cause I could not deal with a child of yours,” Brown said.

Schnapp agreed, saying, “That’s my deal-breaker. No kids.”

While children might not be in their future, they’re not opposed to pets.

“Only dogs,” the actress added. “And separate bedrooms for sure.”

The co-stars reflected on their long friendship, spanning over eight years since they met in the first season of the Netflix hit.

“We have built such a friendship together, I feel, like, and you’re also one of the longest friends I’ve ever had,” said the 18-year-old actress. “But, like, I didn’t grow up in school, so, like, I didn’t have any friends from my childhood. So you really are one of those people for me.”

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Their offscreen chemistry also helped the two with their scenes in the new season of “Stranger Things”.

“I just love being at work and stuff, and I think when you love it and you’re having fun, you can do such a better job,” said Schnapp. “We both encourage each other and cheer each other on when we’re doing well. It’s nice to have that support and, like, it was fun.”

Vol. 2 of “Stranger Things 4” drops on Netflix on July 1.