One of the most familiar sights of summer is the neighborhood ice cream truck. But thanks to a shortage of many popular frozen treats made by Good Humor, you may not be seeing those trucks quite as often in the months to come.

A warm spring caused an early spike in ice cream demand, and factories are having trouble catching up. In addition, one of the main Good Humor factories is about to close its doors for good.

This means ice cream truck classics like Chocolate Eclairs, Toasted Almond bars, Snow Cones and King Cones are sold out. And while distributors have offered generic versions of them, truck operators and customers aren’t interested.

Unilever, the parent company of Good Humor, still has plenty of the grocery store versions of the treats, which are smaller than those sold by ice cream trucks. But that creates a whole new problem for drivers.

“If you get consumers out of the habit of buying the ice cream from the truck,” said Bonnie Knutson, a business professor and expert on consumer behavior at Michigan State University, “it’s going to take a major push to bring them back to make this impulse buy when they can just as easily go to their freezer and eat it at their convenience.”