When you’re in a relationship, it’s pretty much a guarantee that you’re going to fight with your partner at some point – it’s an inevitable part of the deal. That’s right, even happily married couples who have been together for decades still argue every so often, but a new study finds that the topics they choose to argue about determines if their relationship will go the distance.

Researchers at the University of Tennessee arrived at this conclusion after analyzing two groups of a total of 121 happily married couples in their 30s and 70s. The groups were asked to list some of their most and least serious marital problems. Problems related to money, communication, and intimacy were listed as the biggest issues, while topics like jealousy and religion among their least pressing problems.

Then, as researchers observed these happy couples actually discuss some of their problems, they noticed that they were choosing to discuss problems that had a reasonably clear solution. Examples included discussing how to spend their leisure time, or who is responsible for which household chores.

What’s more, the happy couples almost never chose to discuss differences that were harder to resolve – a factor believed to have been critical to their marital happiness.