Contemporary political-culture research has ventured beyond the analysis of citizens’ attitudes in democracies and is increasingly focusing on questions of political support in autocracies. While many of the tradition’s core concepts can easily travel to non-democratic contexts, the empirical analysis of political support for non-democratic regimes presents researchers with a major problem: measurement. How can we assess political support in regimes that are fundamentally different from democracies in both their institutional designs and their functional logics? Currently, research on autocracies simply uses the same survey items that have been used to measure political support in democracies, most commonly questions gauging trust in different institutions. However, given the diverse institutional make-ups of autocracies, we must ask whether this approach is really feasible. To shed light on this question, the contribution sets out to test the comparability of the popular institutional-trust measure across democracies and autocracies. It makes use of a broad range of survey data (Afrobarometer, AmericasBarometer, Arab Barometer, Asian Barometer, Latinobarómetro, World Values Survey) and uses multi-level, multi-group confirmatory factor analysis techniques to test for various forms of measurement invariance.