Some Brooklyn diners have a beef with a local Burger King that they say sold them a vegetarian Whopper but gave them real meat patty instead.

In a story first reported by Eater, a Burger King franchise was offering the “Impossible Whopper” ― or a Whopper made with a vegetarian Impossible Meat patty ― as an option on the Seamless app.

However, the meatless patty is currently only available at Burger Kings in Miami, Florida; Columbus, Georgia; and Montgomery, Alabama, according to CNN.

A manager at the Burger King told Eater that when customers ordered the meatless patty through Seamless, employees would make a beef whopper instead, wrap it in the Impossible Burger wrapper and tell the driver to inform the customer about the switch.

But customers told Eater they were never told their meatless Whoppers actually had meat.

One man told the website he only found out he was accidentally eating meat when he tried to order the “Impossible Burger” at the restaurant and was told it wasn’t actually on the menu.

“I was incredulous,” the man said.

The Impossible Whopper is no longer listed on the Burger King location’s Seamless page, though Fox News reports it’s not clear how many people may have unknowingly eaten the beef version.

The fast food chain blamed the burger brouhaha on a “technology error” from the franchise in a statement to reporters: