Krispy Kreme is sweetening up Halloween with a freebie: The coffee and doughnut chain is offering guests who wear any Halloween costume to participating shops on Oct. 31 a free glazed doughnut, no purchase necessary.

Earlier this month, Krispy Kreme announced its new lineup of Halloween doughnuts– the Krispy Kreme x Ghostbusters Collection. The collection pays homage to the the iconic Columbia Pictures 1984 film’s 40th anniversary celebration.

For a limited time at participating Krispy Kreme shops, patrons can enjoy four doughnuts:

• Ghostbusters Cookies N’ Creme Doughnut made with OREO: An Original Glazed doughnut dipped in chocolate icing, topped with OREO pieces, a dollop of buttercreme with OREO and a No Ghost logo candy.
• Slimer Doughnut – An unglazed doughnut filled with lemon-flavored green filling, dipped in purple and green icing with a Slimer candy.
• Ecto-Sprinkled Doughnut – An Original Glazed doughnut dipped in orange-colored icing and sprinkled with neon sprinkles.
• Stay Puft Marshmallow Man Doughnut Pull-Apart – Original Glazed Doughnut Dots with powdered topping, topped with marshmallow flavored buttercreme and a Stay Puft Marshmallow Man candy.

Also on the lineup: a new drink, the Slimer’s Slime-ade in a signature ectoplasm green.