McDonald’s is short on burgers thanks to the rapper’s popularity.

Last week, fast food chain McDonald’s began selling the “Travis Scott Meal,” a promotional campaign tie-in to rapper and singer Travis Scott. The Travis Scott Meal consists of the musician’s personal favorite McDonald’s menu items: a Quarter-Pounder with cheese, french fries served with barbecue sauce, and a Sprite, all sold for $6. This meal, despite not featuring any unusual items, has proven to be a smash hit for McDonald’s. In fact, the success has been so great, McDonald’s has actually begun to run low on ingredients.

“No doubt, Cactus Jack sent you … A LOT of you. SO many of you,” McDonald’s said in a statement, referencing Scott’s personal record label.

“In fact, it’s been so lit, some of our restaurants have temporarily sold out of some of the ingredients in the meal,” McDonald’s continued. “We’re working closely with our suppliers, distributors, and franchisees to resupply impacted restaurants as quickly as possible. Stay tuned and don’t worry, we’ve got more surprises from Cactus Jack coming soon.”

Supply control is a common tactic employed by McDonald’s for their limited-time items like the McRib. Ingredients have also been monitored carefully ever since the COVID-19 pandemic began affecting meat plants. This is the very first time, however, that McDonald’s has run short of ingredients, and it’s due almost entirely to the popularity of the Travis Scott Meal rather than the pandemic. For the time being, the ingredients present in a traditional Quarter Pounder may not be available at all McDonald’s locations.

Some McDonald’s employees have also been reporting a bit of confusion related to the meal. Some customers use slang terms to order the Travis Scott Meal, such as “Cactus Jack sent me,” which has been confusing to some cashiers. To address this, a memo was sent out from Morgan Flatley, McDonald’s US chief marketing officer, and Vicki Chancellor, head of McDonald’s Operator’s National Advertising Fund

“Various Travis Scott Meal marketing materials include the line, ‘Say Cactus Jack sent you’, leading some customers to say, ‘Cactus Jack sent me’ or other social-media-inspired variations including: ‘It’s lit, sickomode,’ ‘The Fornite guy burger,’ or ‘You know why I am here’ (while playing Travis Scott music),” the memo said. “To reduce confusion, please make crew aware of these monikers or alternate ordering methods.”