Over the last decade, policies of mandatory integration have increasingly spread over Western Europe. They require immigrants to follow language and country-knowledge courses and/or to succeed tests. Social scientists have debated on the objectives, functions and the consequences of these tests. They disagree about whether these policies contribute to better economic, social and political integration (Wallace Goodman, 2015); whether they are a disguised immigration tool (Böcker and Strik, 2011), a recipe to show the majority population immigration policy is under control (Adam, 2013) or an assimilative tool demonstrating the neo-communitarian trend leading to a 'thickening' of citizenship (Etzioni, 2007). The demonstration of these claims have however rarely been tested empirically. Policy evaluation is rare and, furthermore, few studies focus on how these courses are perceived and lived by the immigrants themselves. This study aims to understand the contribution of these courses through the eyes of the immigrants. Through semi-directive interviews with voluntary and compulsory participants in Flemish integration courses offered in Antwerp, Brussels and Ghent, we verify the claim by Löwenheim & Gazit (2009) that mandatory integration courses risk to be interpreted as hostile assimilationist instruments, mainly serving to authorize state authority. The Belgian multi-national and federal context allows to verify this claim at the sub-state level, investigating if and how Flemish integration courses contribute to identification with Flanders, political socialization and an increase of Flemish (sub-)state power.