The invention provides a hair shaping composition suitably for topical application to hair, the composition having a pH of 4 or less and comprising, in an aqueous continuous phase: (i) at least 0.5% by weight based on the total weight of the composition of a first component selected from D-glucono-δ-lactone, D-glucono-γ-lactone, D-gluconic acid and mixtures thereof； (ii) at least 0.1% by weight based on the total weight of the composition of a second component selected from glyoxylic acid, glyoxylic acid hydrate, salts thereof and mixtures thereof； in which the weight ratio of first component (i) to second component (ii) in the hair shaping composition ranges from 10:1 to 1:10.
