In recent years, several scientific disciplines have been undergoing replication crises, and in response, preregistration has been offered as a solution to replicability problems. In this paper, I will draw connections between this new focus on preregistration and an older debate in the philosophy of science, namely predictivism—the thesis that predictions are epistemically superior to accommodations. Specifically, I shall argue that predictivism justifies preregistration. As it turns out, predictivists of all stripes have subtly different reasons to support preregistration. This unity (...) is significant because firstly, preregistration proponents often seem to be implicitly committed to stronger versions of predictivism, but strong predictivism has long been deemed untenable by philosophers of science. Furthermore, the efficacy of preregistration in dealing with Questionable Research Practices (QRPs) like p-hacking and HARKing is at best contentious, which blocks a straightforward empirical justification of preregistration. Although empirical validation of preregistration—which need not be based on preventing QRPs—will eventually be required, it would be nice to have a principled justification for preregistration while we await the empirical evidence. I will also argue that preregistration offers something in return to predictivism: the former bolsters the latter by serving as a counterargument to accommodationism—the antithesis of predictivism. (shrink)