People really want their adult Happy Meals, and it’s stressing out McDonald’s frontline staff.

On Monday, McDonald’s started selling Happy Meals—normally targeted to children—to adult customers. And like the child Happy Meals, the special offering comes with a toy, as part of a collaboration with Cactus Plant Flea Market, a streetwear brand. The promotion runs until the end of the month.

But while potential customers were excited about the special promotion—and the limited edition toys—McDonald’s employees were less enthusiastic about dealing with a rush of customers. “I can see the stress among my coworkers,” one employee told Kotaku.

Employees are venting on social media, like TikTok and Reddit. “Y’all, please stop ordering these,” posted one employee on TikTok. Another employee wrote, “They going crazy with the adult Happy Meals,” over a video showing the number of Happy Meal orders.

“New Adult Happy meals are killing me,” said one post on the McDonald’s employees subreddit.

“We ran out of boxes the first day we had them, ran out of toys the second, and on the third day we had to say the truck doesn’t come till tomorrow,” wrote one commenter elsewhere on the subreddit. “It’s been…not fun.”

“Leading up to the launch, we prepped crew with training and resources in anticipation of higher traffic in restaurants,” a McDonald’s USA spokesperson told Fortune, continuing to say that “our restaurant crew members are the best in the business, and we appreciate everything they’re doing to serve customers during this limited-time promotion.”

This isn’t the first time a McDonald’s promotion has caused hassle for the staff.

In 2017, McDonald’s revived its Szechuan dipping sauce for one day as part of a marketing exercise with Adult Swim show Rick and Morty. Desperate fans swarmed restaurants hoping to get some of the limited supply, leading to long lines, disruptive customers, and even calls to law enforcement. The chaos was worsened by poor communication from McDonald’s as to which restaurants were taking part in the promotion, meaning customers flocked to sauce-less restaurants.

Customer chaos happened again in 2021, when McDonald’s revived its Pokémon Happy Meals, complete with collectible cards, to celebrate the video game franchise’s 25th anniversary. Unfortunately, the promotion occurred during a bubble in Pokémon trading cards, in which cards could be flipped for a 350-times return.

Some restaurants were forced to restrict sales of the Pokémon Happy meals to stop scalpers from buying up all the available Happy Meals and flipping the included trading cards on eBay.

It’s not just McDonald’s. Last year, a tweet from a purported Starbucks employee went viral after the worker complained about customers adding too many modifiers to their drinks, leading to many other baristas complaining about the stress of completing similarly complex orders.