This paper argues for a unified account of semantic and pragmatic infelicity. It is argued that an utterance is infelicitous when it communicates an inconsistent set of propositions, given the context. In cases of semantic infelicity the relevant utterance expresses a set of inconsistent propositions, whereas pragmatic infelicity is a matter of the utterance conflicting with contextual expectations or assumptions. We spell out this view within the standard framework according to which a central aim of communication is to update a body of information shared among the participants. We show that this account explains different kinds of infelicity for both declarative and non-declarative utterances. Further, the account is seen to make correct predictions for a range of cases involving irony, joking, and related non-assertoric utterances.