This article relates the controversy over the process of prison privatization in France during the mid-1980s. It recalls the origins of the project, then focuses on the parliamentary battle which it gave birth to. The initial ambition of a total privatization became narrower and gave way to a seemingly superficial transfer, related to an indefinite expansion of the prison system capacity. This process can be seen as a key event in the extension of an economic style of reasoning in the criminal justice system. Furthermore, this trial involved not only a legal redefinition, but the actualization of a political rationale sealing the alliance between rule of law and managerialism.