Not many cities take their hot dogs as seriously as Chicago. And though what constitutes a proper Chicago-style hot dog can vary depending on who you ask, one rule always seems to remain firm: no ketchup. Now, that mantra has even seeped into the city’s sports culture, taking center stage on a shirt that’s just been put up for sale by the Chicago White Sox.

New this year at the Chicago Sport Depot, the athletic gear outlet adjacent to Guaranteed Rate Field (home to the Chicago White Sox for those inevitably struggling to keep up with ballpark naming rights), is a jokey T-shirt that reads “NO KETCHUP IN Chicago”—with the “Chicago” written out in a classic cursive black-and-white White Sox font. According to Eater, who spoke with Delaware North retail operations manager Barbara Bee, the idea for a hot dog-focused shirt actually came from a former employee who got the silly concept sent over to Major League Baseball for approval.

The shirt stuck, and now Sox fans can simultaneously show their home team love with their ketchup hate—assuming they’re willing to throw down the $39.99 that the Under Armour-produced piece is retailing for. Sure, a nearly identical, un-licensed sentiment could be sold sans Sox font and Under Armour logo for a lot cheaper. But then again, no one has ever taken a trip to the ballpark expecting to get a good deal on food and merch.