I address the question whether Dummett's manifestation challenge to semantic realism can be disarmed by reflection on the compositionality of meaning. Building on work of Dummett and Wright, I develop in 1-2 what I argue to be the most formidable version of the manifestation challenge. Along the way I review attempts by previous authors to deploy considerations about compositionality in realism's favour, and argue that they are unsuccessful. The formulation of the challenge I develop renders explicit something which I argue to be implicit in Dummett's and Wright's presentations: that the challenge depends on a contention about the constitution of speakers' states of declarative sentence understanding: i.e., that many such states incorporate abilities to recognize whether the associated sentences' truth conditions are satisfied. In (sic)3 I argue that reflection on the compositionality of meaning reveals, first, that this contention must be rejected by the realist, and second, that it is unmotivated. This result does not settle the debate over the manifestation challenge, but it implies that the onus of argument does not currently rest with the realist.