Gluten-free diners can now enjoy a sandwich at Chick-fil-A with an actual bun.

The chicken chain on Monday rolled out a gluten-free bun nationwide. It's made with quinoa and amaranth and sweetened with molasses and raisins.

"We know our customers are looking for more gluten-sensitive alternatives. They asked, and we listened," Leslie Neslage, senior consultant of menu development at Chick-fil-A, said in a statement. "We heard positive feedback in test markets that the bun tastes better than some other gluten-free breads."

The bun costs an extra $1.15 and comes individually packaged. Customers will have to assemble their own sandwich because Chick-fil-A kitchens are not gluten-free and this is the only way that chain can prevent cross-contamination.

The chain estimates that about 18 million Americans have gluten sensitivity, like celiac disease or a wheat allergy, or a preference for gluten-free foods.

"Our hope is that the Gluten-Free Bun addition opens up options for gluten-sensitive customers to enjoy more of our menu," Neslage said.