Little is known about what influences high-achieving, low-income students' persistence in higher education, despite extensive work on their enrolment decision. This paper investigates the role of credit constraints. Using exhaustive administrative data for France, I estimate the impact of automatically granting generous additional aid to enrolled high-achieving, low-income students. Eligibility is communicated too late to affect initial enrolment, allowing me to recover the pure effect on the intensive margin. I find this aid had precisely estimated null effects on persistence, graduation, and did not induce switches to higher quality degrees. This suggests non-financial factors largely explain these students' observed attrition.