Cheech Marin and Tommy Chong, the comedy pair of the 1970s and ’80s, are back to sell a new version of the “magic brownie.”

To help General Mills introduce its Fiber One 90-calorie brownies, Cheech and Chong donned their stoner personas for a marketing campaign video titled “Cheech and Chong’s Magic Brownie Adventure.”

In the sketch, which was shot in two days in June, the two set out to deliver what they believe is a van full of marijuana-laced brownies, but they find out these treats are actually high on fiber.

“Because now that you’re getting older, you need a new kind of magic from your brownie,” says the video.

On General Mills’ blog, Fiber One marketing manager Jim Wilson said the idea came about during a brainstorming meeting in 2010. General Mills said it hopes the new campaign will make people laugh as it spreads the message about the magic fiber benefits of its new brownies.