How do radical right-wing ideas become normalized? This study investigates in how far liberal value frames (e.g. framing an issue as protecting women’s rights or gay rights) lead to higher tolerance for Islam-critical positions. We test this by conducting a survey experiment where we vary whether an anti-Islam position is presented as a liberal value frame or not, and which party sends the message (mainstream/radical right). We also vary the gender of the message sender (male/female), and their sexual orientation (in a heterosexual/homosexual relationship). We expect that messages framed as a defense of liberal values lead to higher tolerance for Islam-critical positions. We also expect that congruence between the liberal value frame and the sender characteristics will strengthen the normalizing effect of the frame. By testing the effect of liberal value frames on anti-Islam sentiment, this study makes an important contribution to our understanding of how radical right-wing positions become normalized and accepted into the mainstream. At a time where we are witnessing a rise of radical right-wing parties and ideas across Europe, this study adds novel experimental evidence as to what the drivers underlying the normalisation of radical right-wing positions are.