This paper explores the attitudes of expatriate workers towards the future of migration to the Arab Gulf states. We conduct an online survey and framing experiment administered to more than 2900 expatriate workers in Kuwait and Qatar. We find that Arab migrants are less supportive of future migration than other migrants and also exhibit high levels of ethnic-group bias in favor of fellow Arabs. Evidence from the framing experiment suggests that Arab migrants disfavor Indian workers, even though workers from South Asia are less likely to pose competition for jobs. Our findings provide empirical evidence for ethnic boundary policing within the migrant community and speak to the conditions that encourage anti-migrant sentiment and in-group favoritism among Arab expatriate workers in the Gulf region.