Becoming a parent changes a lot of things: Your body, the amount of laundry in your home, your relationship with your spouse and, of course, your relationship with your in-laws. Along with all the joy that children bring, they also add a new dynamic that may increase some tension—which isn’t fun if your relationship with your mother-in-law is already fraught with disagreements.

According to a recent study by the Academy of Finland, this is why couples with kids fight with their in-laws more than couples who don’t have children. Based on their findings, the relationships between adults and their in-laws becomes more “kin-like” after children enter the picture. Disputes between daughters-in-law and mothers-in-law were especially common when grandmothers provided childcare.

But there was a big upshot to the findings: By feeling more like family, we’re more inclined to help each other out.

To maximize those benefits while minimizing the downfalls of close in-law relationships, Angela Bowen, author of Today's Grandmother: Your Guide to the First Two Years, told Motherly that it’s essential to set boundaries.

“You have to say, ‘This is our child and this is how we are doing things,’” she explained. That may not be entirely welcomed news to a grandparent who felt confident in their own parenting abilities—but it is important to address in the beginning.

Bowen also said she wasn’t surprised adding child care responsibilities into the relationship was linked to more tension. Again, she said it helps to talk about what the grandma should or shouldn’t do—as well as make her feel appreciated. (If she isn’t compensated for her baby-sitting duties, a spa day or an occasional home-cooked dinner is a great way to show the work is valued, Bowen suggested.)

Regardless of whether the grandparents’ house is going to double as a daycare, Bowen said couples may avoid some in-law fights by having discussions about modern day pregnancy and infant care techniques. “If you are reading a book, get her a copy—a new copy for her—so you’ll be on the same page.”

Bowen also suggested each partner deal with their own parents when it comes to tricky subjects. And she also advised being mindful of how exciting this time is in the grandparents’ lives, too.

“In the end, it’s your child,” she said. “But it’s great to be a grandmother.”