Foreign students are one of the most significant immigrant categories in many North American and Western European countries. Yet as their numbers have swelled, many governments have experienced increasing pressures to cap their entry. This is true despite the sizable benefits that foreign students bring to host countries, and despite standard political economy concerns about immigrants—that they take away jobs or abuse public entitlements—not applying to foreign students. We field a nationally-representative survey experiment in the U.K., one of the top destinations for foreign students, to examine potential activators of public support for capping the number of foreign students. Results show that support for caps is most activated when citizens are primed to think about foreign students competing with domestic students for scarce admissions slots at universities.