This article focuses on the development of class-specific inequalities within German universities. Based on data on the social origin of students, doctoral students, and professors in the long-term cross-section, the article views the empirically observable dynamic of social closure of higher education since the 1950s. The focus of interest is on the level of the professorship. Data show that career conditions for underprivileged groups have deteriorated again. This finding is discussed in the context of social closure theories. The article argues that closure theories consider social closure processes primarily as intentional patterns of action, aimed at a strategic monopolization of participation, and securing social power. Such an analytical approach means that unintended closure processes remain understudied. Our conclusion is that concealed modes of reproduction of social structures ought to be examined and theorized more intensively due to their importance for the elimination of social inequality within universities.