Compulsory voting is sometimes thought to be justified in democracies because it promotes high levels of voting and mitigates inequalities of turnout amongst social groups. Proponents of compulsory voting also argue that it helps to prevent the free-riding of non-voters on voters. This article casts a sceptical eye on both arguments. Democratic citizens do not have a duty to promote their self-interest,and their duties to others do not generally require them to vote, or to attend the polls. So, while people are sometimes morally obliged to vote, and to vote one way rather than another, legal compulsion to vote or to turn out is generally unjustified and inconsistent with democratic government.