Libertarianism stands for maximum individual liberty and thus against any kind of slavery.
Apparently, then, libertarianism countenances the legitimacy of selling oneself into slavery, and enforcing the slavery contract against those who change their minds. Thus it seems that the ideals of self-ownership and sanctity of contract can come into conflict with the ideal of maximum liberty and the rejection of slavery. On this issue, libertarians are divided. Robert Nozick, in Anarchy, State, and Utopia, maintained that slavery contracts were permissible and indeed enforceable. Since Nozick is the only libertarian most academic philosophers have ever read, many of my colleagues, knowing my libertarian sympathies, assume that I too favor slavery contracts.