The main lesson from Gettier cases is that while one cannot know a proposition by luck, one can hold a lucky true belief justifiedly. Possibly because the latter is taken for granted, the relationship between epistemic justification and epistemic luck has been less discussed. The paper investigates whether luck can undermine doxastic justification, and if so, how and to what extent. It is argued that, as in the case of knowledge, beliefs can fall short of justification due to luck. Moreover, it is argued that justification-undermining luck is a problem for both internalist and externalist conceptions of justification. Accordingly, it is shown that epistemic luck is a more widespread phenomenon than many in epistemology commonly assume.