Canton, Mass.-based Reebok International has a bone to pick with sporting goods rival Nike Inc. On April 3 Reebok filed suit against the Oregon company in the U.S. District Court for the Eastern District of Texas, accusing Nike of infringing its “Collapsible Shoe” patent.

According to the filing, several Nike shoes, including the “Free Trainer” and “Free Trail” models, infringe Reebok’s flexible sole technology, which allows consumers to collapse shoes for travel.