University credentials are among the most visible signals on a graduate’s CV, but it remains unclear whether and why employers respond to institutional prestige, a shared alma mater, or neither. In this letter, we employ a state-of-the-art factorial survey experiment with genuine recruiters to shed further light on this question. We find that sharing an alma mater indeed increases perceived collaboration potential in Belgium. This does not, however, translate into a higher propensity to invite candidates for an interview, nor does mentioning a degree from a higher-ranked university. The alma mater effect therefore appears, at least in Belgium, not to generate a prestige premium, but rather to reflect a narrower perception of interpersonal fit.