We consider agent-denoting nominalizations like the finder of the wallet, contrasting them with the better-studied action/event-denoting nominalizations. We show that in English, Sakha, and Mapudungun, agent-denoting nominalizations can have none of the verbal/clausal features that event-denoting nominalizations often have: they cannot contain adverbs, voice markers, aspect, or negation. The one apparent exception to this generalization is that (only) Sakha allows accusative-case objects in agentive nominalizations, but we show that this is due to Sakha's special rule of accusative case assignment, not to a difference in the structure. We explain these restrictions by saying that agentive nominalizers have a semantics like that of a Voice head (Kratzer 1996). Given this, the natural order of semantic composition implies that agentive nominalizers, like Voice, must combine directly with a bare VP. We conclude by presenting the results of a seventy-eight-language survey, confirming that human languages in general avoid clause-like syntax inside agentive nominalizations, although it is permitted in reduced relative clauses, which may look superficially similar.