Drawing from ethnographic data from 48 households in four villages in rural Anhui, this study explores how two practices known for upholding son preference are affected by rural–urban out-migration, with a particular focus on the division of labour in agricultural work and patrilocality. The study deploys the concepts of an intergenerational contract and the “unsubstitutability” of sons and finds that a weakening of the intergenerational contract can take place without substantially challenging the unsubstitutability of sons. The study concludes that although male out-migration undermines the argument that sons are needed to secure male manual labour in family farming, the vital role of male labour as a rural livelihood strategy largely persists. Moreover, although the study identifies migration-induced exceptions, patrilocality remains the main organizing principle for social and economic life for both male and female migrants. Hence, the study finds little support for the prospect that migration is attenuating son preference in rural China.