(CNN) – The maker of Chips Ahoy has issued a voluntary nationwide recall of one of its popular cookies.

Mondelez International announced the recall for certain 13-ounce packages of Chewy Chips Ahoy. The company cited a possible “unexpected solidified ingredient” that has led to “reports of petential adverse health effects.”

The voluntary recall is limited to packages with “best sell by” dates of Sept. 7, 8, 14 and 15 of 2019 in the U.S.

Customers who have the products should not eat them.