Kylie and Kendall Jenner’s underwear designs may land them in court.

According to legal documents obtained by TMZ, the celebrity sisters are being sued over lace patterns featured in their popular lingerie line. The plaintiff is Klauber Bros., Inc.—a 161-year-old company that specializes in original art design for lace production.

Per the company’s website:

Most of our patterns are copyrighted and based on original artwork. Klauber has a reputation for utilizing the latest machinery in a unique and creative fashion to develop new designs. More important is our focus on breakthrough techniques that advance the art of lace making.

Klauber Bros. claims the Jenners used one of its copyrighted lace designs on two of its pieces: the Kylie Thong Panties and a black slip dress. TMZ posted side-by-side images of Klauber Bros.’ lace patterns and those featured on the Jenners’ garments. The designs look very similar, so much so that the plaintiffs are demanding the sisters to stop selling the pieces online and in stores. The company is also seeking all of the profits from the thong and slip sales, which could result in a huge pay day.