How do international laws affect citizens’ willingness to accept refugees? In full and partial democracies, citizens’ attitudes can influence national policy on accepting refugees. A growing literature suggests international institutions can influence citizens’ attitudes on foreign policy issues, but those studies are almost entirely confined to domestic human rights and U.S.-based respondents; none consider refugee policy. Using data from a survey experiment administered in September 2017 via face-to-face interviews with 1335 Turkish citizens, we investigate how international norms affect citizens’ willingness to accept refugees. Our findings are surprising: reminding people about the government’s responsibility under the Refugee Convention to accept refugees triggers a backfire effect, decreasing support for accepting them. This effect appears driven by respondents who support the nationalist-populist incumbent party and by lower-educated respondents. We therefore provide evidence that international refugee law – and perhaps international institutions generally – can trigger a political backlash, undermining the very policies that they promote.