The ongoing transformation of work has been increasing the number of working relationships not falling within the domain of labour law. Non-standard and contingent working arrangements, most recently those prompted by the so-called gig economy, struggle to meet customary employment tests, since the employee/self-employed dichotomy has long been eclipsed. As this article will argue, the Court of Justice of the European Union, in shaping the scope of EU labour law, has been looking beyond the traditional categories. Starting from the area of the free movement of workers, the Court has built a common European concept of worker, broader than that of ‘employee’ endorsed by national jurisdictions, applying it to an increasing body of EU social legislation. Because of the primacy of EU law, the Court’s approach is bound to influence national laws.