The subject of the invention is a method for permanently changing the shape of keratin fibres, in particular human hair, comprising the following steps in the specified order: (A1) applying a permanent waving agent (a) to the keratin fibres； (A2) leaving the permanent waving agent (a) to take effect for a period of from 2 to 60 minutes； (A3) rinsing out the permanent waving agent (a) from the keratin fibres； (B1) applying a cosmetic agent (b) to the keratin fibres； (B2) leaving the cosmetic agent (b) to take effect for a period of from 2 to 60 minutes； (B3) rinsing out the cosmetic agent (b) from the keratin fibres； (C1) applying a fixing agent (c) to the keratin fibres； (C2) leaving the fixing agent (c) to take effect for a period of from 2 to 60 minutes； (C3) rinsing out the fixing agent (c) from the keratin fibres； where the permanent waving agent (a) contains one or more keratin-reducing compounds, the cosmetic agent (b) contains one or more aliphatic C2-C8 dicarboxylic acids and/or physiologically acceptable salts thereof, and the fixing agent (c) contains hydrogen peroxide. A further subject of the present invention is a kit-of-parts comprising the agents (a), (b) and (c) packaged separately in the containers (A), (B) and (C).
