Standard explanations of anti-immigrant sentiments as well as explanations of the voting behavior of ethnic minorities would both predict voters with an immigrant background should be less inclined to support anti-immigration policies than comparable natives. We show this was not the case in the Swiss referendum “against mass immigration” held in 2014. In this referendum voters with an immigrant background showed surprisingly high levels of support to the initiative to restrict immigration, which were comparable to those expressed by natives. To explain this puzzling finding, we propose to look at two alternative (but not mutually exclusive) drivers of policy preferences previously overlooked in the voting literature: ethnic boundary making and labor market competition. We show that accounting for Secondo identity (a boundary-making identity specific to the Swiss ethnic hierarchy) and exposure to occupational and geographical labour market competition can explain the puzzle of immigrants’ support for immigration restrictions.