The present invention relates to a process for reshaping keratin fibers, preferably hair, comprising the steps of: (i) applying onto the keratin fibers a composition comprising (a) at least one diol selected from C4-5 diols, wherein the composition has a pH of from 8.0 to 13.5, preferably from 8.5 to 12.0, and more preferably from 9.0 to 11.0; (ii) heating the keratin fibers; and (iii) optionally rinsing and/or drying the keratin fibers. The present invention can reshape keratin fibers without reducing and oxidizing the keratin fibers, and can provide superior reshaping efficiency, such as strong wave intensity and many curls.