The fast food chain is advertising the change with a somewhat unsettling campaign.

Fast food chain Burger King announced today that going forward, they will be removing all artificial preservatives, flavorings, and colors from their signature Whopper sandwiches. To advertise this new change, the chain has begun an advertising campaign showcasing a Whopper that has been sitting out for 34 days. The Whopper is shown to be covered in mold and decomposing, apparently to prove that the sandwich contains no additives whatsoever.

This is similar to a move McDonald’s made back in 2018 wherein additives were removed from several of their most well-known products, in addition to a change in the recipe of their famous Big Mac sauce.

Despite the unsettling appearance of the moldy Whopper, it seems to have gotten Burger King’s message across; commentors of the ad on YouTube have said that while the moldy Whopper is disgusting, they are relieved that the burgers will no longer contain additives.

Over 4,000 Burger King locations have already begun selling additive-free sandwiches. The chain estimates that all of its locations will be selling additive-free Whoppers by the end of 2020, though they have not stated whether they intend to carry this change beyond the Whopper.