This paper argues that the term ‘passive’ has been systematically misapplied to a class of impersonal constructions that suppress the realization of a syntactic subject. The reclassification of these constructions highlights a typological contrast between two types of verbal diathesis and clarifies the status of putative ‘passives of unaccusatives’ and ‘transitive passives’ in Balto-Finnic and Balto-Slavic. Impersonal verb forms differ from passives in two key respects: they are insensitive to the argument structure of a verb and can be formed from unergatives or unaccusatives, and they may retain direct objects. As with other subjectless forms of personal verbs, there is a strong tendency to interpret the suppressed subject of an impersonal as an indefinite human agent. Hence impersonalization is often felicitous only for verbs that select human subjects.