In the context of a longstanding dispute over the tax treatment of dividends in France (the “précompte mobilier” dispute), the ECJ ruled, for the first time, that a Member State had failed to fulfil its obligations under EU law because its Supreme Court did not make a reference for a preliminary ruling to the ECJ. This note comments on the decision in Commission v. France (Case C-416/17), first providing background and then assessing its impact on future case law developments.