European majority group members increasingly perceive threats to national continuity, which in turn leads to defensive reactions, including prejudice against Muslim immigrants. However, according to self-affirmation theory, individuals can respond in a less defensive manner if they have affirmed positive aspects of their self-concept (self-affirmation) or their social identity (group-affirmation). In the present research, we test the potential of affirmation procedures as tools for reducing prejudice towards Muslim immigrants when national continuity is threatened. We examine the impact of personal vs. normative attachment to Christian roots of national identity on the efficacy of affirmation procedures, and the congruence between the threatened and the affirmed domains of the self. Results show that group-affirmation reduced opposition to Muslims’ rights amongst participants personally attached to the idea that national continuity is based on Christian roots. The discussion stresses the importance of non-congruence between the threatened domain of the self and the affirmed domain for the design of affirmation procedures. © 2019 Elsevier Ltd