On 30 April 2019, the Court of Justice of the European Union (CJEU) decided in Opinion 1/17 that the chapter on investor-State dispute settlement (ISDS) in the Comprehensive Economic and Trade Agreement between Canada, of one part, and the European Union and its Member States, of the other part (CETA) is compatible with EU primary law. On 29 January 2019, Advocate General Bot had already reached the same conclusion (for an analysis, see here). Opinion 1/17 removes a significant obstacle to the ratification of CETA by the EU Member States and the ratification of investment protection agreements with, for example, Singapore and Vietnam, which contain similar chapters on ISDS. The Opinion also significantly boosts the European Union negotiating position in the ongoing United Nations Commission on International Trade Law (UNCITRAL) negotiations on ISDS reform. At the same time, the Opinion might, to some extent, tie the hands of the European Union in negotiating in that forum.