The present invention is concerned with, as a hydrocurable composition, a mixture of an oxazolidine-functional polymer and a compound of a monomeric or polymeric character having a plurality of acryloxy groups. The first-mentioned polymer contains a plurality of pendant groups containing 2,2-dialkyl oxazolidine groups. The mixture of these two components can be stored under anhydrous conditions in a closed container without co-reaction so that a one-pot or one-package composition can be made up with many conventional ingredients of coating compositions other than aqueous components and stored without gelling until the time for application when the composition may be applied at ambient temperature and humidity whereupon reaction between the main two components mentioned above occurs in the film deposited and the film set up.