Civic duty has been perceived as a key determinant of turnout. That is, while dutiful citizens turn out in large numbers, those who conceive of voting as a choice do less so. The strong correlation between civic duty and turnout might be due to reverse causation, however. Specifically, individuals might adapt their sense of duty according to previous voting behavior. In this article, we leverage Belgium’s compulsory voting system and the age-based discontinuity for the right to vote, and estimate the effects of being treated with participation on civic duty. We do not find “treated” citizens to be more likely to report civic duty than their “non-treated” counterparts. This finding holds across a series of robustness tests, and suggests that civic duty is exogenous to the vote.