This article brings to bear findings from the debate on the boundary problem in democratic theory on discussions of workplace democracy to argue that workplace democrats’ focus on workers is unjustified and that more constituencies will have to be included in any prospective scheme of workplace democracy. It thereby provides a valuable and underdiscussed perspective on workplace democracy that goes beyond the debate’s usual focus on the clarification and justification of workplace democrats’ core claim. It also goes beyond approaches like stakeholder theory in law and economics that determine decision-making rights without taking into account genuinely democratic considerations. My discussion proceeds by considering three principles for inclusion from democratic theory for the specific case of the corporation. I submit that two of them, the all-coerced and the all-subjected principle, are not appropriate for this specific case, because they cannot capture the distinguishing features of the corporation. The all-affected principle however is appropriate but has a very wide range. I further argue that this is not as big of a problem as it first might seem and that this principle is still the most appropriate for defining the demos of the democratic corporation. The article closes by pointing out the consequences of this result for the workplace democracy debate and for the legitimacy of the market as a coordination mechanism.