Starbucks urged the U.S. Court of Appeals for the District of Columbia Circuit on Friday to reverse a National Labor Relations Board finding that a manager at the coffee chain illegally prohibited an employee from distributing union pins inside a store.

The NLRB argues that the employee likely would’ve believed the ban extended even in non-public areas of the store, such as back rooms, and during paid breaks, a prohibition that would violate the National Labor Relations Act.