This article analyses the relationship of the proposed Common European Sales Law (CESL) and the rules on mandatory and overriding provisions in private international law. The author argues that the CESL will not achieve its stated aim of taking precedence over these provisions of national law and therefore not lead to an increase in cross-border trade. It is pointed out how slight changes in drafting can overcome the collision with mandatory provisions. The clash with overriding mandatory provisions, the author argues, should be taken as an opportunity to rethink the definition of these provisions.