A combination of formal causation and natural-kind essentialism has good prospects. After all, natural-kind essentialists are under pressure to accept that natural kinds ground or formally cause the properties that characterize them. However, natural-kind essentialists are committed to the claim that natural kinds essentially depend on the properties that characterize them, such as the property of unit negative charge in the case of the electron kind. We argue that, given plausible assumptions about grounding and dependence, these claims clash. After presenting the problem, we consider and criticize ways in which natural-kind essentialists could try to avoid it