Nintendo will start taking action against real-money transactions in Animal Crossing: New Horizons.

Nintendo said on Monday, June 15 that it will move to eliminate real-money transactions when players buy and sell villagers and other items in the game. In a statement to Japanese website J-Cast, Nintendo said that using real money to buy and sell virtual goods is a violation of its terms of service. The company didn’t divulge how it would handle incidents but said that it will evaluate each transaction on a “case by case basis.”

Since its launch in March, the wildly popular Animal Crossing: New Horizons has had a robust digital trade community where people regularly buy and sell villagers and items. Some of those people buy those goods with in-game money, like Nook Miles and bells, which appears to be an allowed practice.

In other cases, however, players are using PayPal, Venmo, and other real-world services to pay actual cash for their desired characters. There have even been websites created for the sole purpose of buying and selling villagers from the game.

When they are paying for items and villagers, buyers are finding it’s an expensive prospect. In fact, eBay is awash with listings allowing players to buy villagers from $5 up to $25 and beyond. And along the way, Nintendo finds itself cut out of the equation.

Whether Nintendo will actually be able to enforce its new policy, however, remains to be seen. Since the transactions occur on third-party platforms like eBay, Twitter, and elsewhere, it may be difficult for Nintendo to accurately determine if players purchased villagers and how. Indeed, the company didn’t say how it intends to make determinations and ban accounts and did not immediately respond to a Digital Trends request for comment on the matter.

It’s a problem Epic Games has tried to deal with in Fortnite, where players have used real money to buy rare skins and other items from the game. And although Epic Games has banned the practice, a quick search on eBay reveals plenty of rare skins for people to buy outside the confines of the game.