Abstract The European Court of Justice's Forster judgment can lead to a reduction of legal uncertainty caused by integration requirements for third-country nationals. The judgment has created a strong ''assumption of integration'' after five years of legal residence because it equalised integration requirements for European students to access the welfare system of host Member States with a requirement of five years legal residence. Almost all pieces of European legal migration law also contain five-year residence requirements after which the status of third-country nationals improves. However, these improvements are mostly subjected to the fulfilment of additional integration requirements. To keep coherence with European law, courts will not be able to disregard the Forster ''assumption of integration'' when assessing the legality of integration conditions for third-country nationals put in place in addition to residence requirements.