ST. LOUIS COUNTY, Mo. – Friday the 13th only happens every 11 years in October. So to celebrate the rare spooky occasion, ‘Duck Donuts’ is offering a special one-day deal.

If you buy a dozen donuts in-shop or online, you can get the 13th one free, as long as it doesn’t have any premium toppings. Just use the code ‘Friday-13’ when ordering.

October at Duck Donuts also means the return of the ‘Spooky Box.’ It’s filled with frightening donut combinations, such as maple bacon with raspberry or a chocolate donut with Oreos and gummy worms.

Those are available until the end of the month.