Social contract theory offers a powerful method and metaphor for the study of organizational ethics. This paper considers the variant of the social contract that has arguably gained the most attention among business ethicists: integrative social contracts theory or ISCT [Donaldson and Dunfee: 1999, Ties That Bind (Harvard Business School Press, Boston)]. A core precept of ISCT - that consent to membership in an organization entails obligations to follow the norms of that organization, subject to the moral minimums of basic (...) human rights - is a reasonable and appealing notion. One potential challenge for those attempting to apply this idea, however, lies in the dynamic nature of social norms. Organizational norms evolve, often through the conscious efforts of community members and leaders. As currently formulated, ISCT offers a framework that under-appreciates the evolving nature of moral norms. In this paper, we extend ISCT by considering the circumstances under which the terms of and parties to social contracts change. We also consider a number of principles that should be considered as the terms and parties to organizational social contracts change. (shrink)