Critical thinking is frequently proposed as one of the most important learning outcomes of a university education. However, to date, it has been difficult to ascertain whether university students in low-income contexts are improving in their critical thinking skills, because the limited studies in this domain have relied on instruments developed in Western contexts, despite the clear dangers of such an approach. Cultural bias in assessment can best be overcome by explicitly developing tests for use in specific contexts. However, resource constraints often prevent this possibility. An alternative strategy is to adapt an existing instrument for use in a particular context. Although adaptation is the norm for high-stakes cross-cultural assessments, it is often not attempted for single country research studies. This may be due to an assumption that adaptation is excessively technical or will add significantly to a study timeline. In this article, which relies on data from a recent study in Rwanda, we present a methodology for adapting a performance-task-based assessment of critical thinking. Our experience with this methodology suggests that small teams can adapt instruments in a relatively short time frame, and that the benefits of doing so far outweigh any cost.