Agent for treating fibers containing keratin, in particular human hair, having in a cosmetically acceptable carrier, (a) at least one amphiphilic, cationic polymer comprising at least one structural unit of formulae (I) to (IV), wherein R1 and R4 are independently hydrogen or a methyl group; X1 and X2 are independently oxygen or a NH group; A1 and A2 are independently ethane-1,2-diyl, propane-1,3-diyl or butane-1,4-diyl; R2, R3, R5 and R6 are independently a (C1 to C4)-alkyl group; R7 is a (C8 to C30)-alkyl group; (b) at least one other film-forming cationic and/or stabilizing cationic polymer; and (c) at least one film-forming non-ionic and/or stabilizing non-ionic polymer. The invention also relates to the use of the agent for temporarily styling hair and for haircare, particularly as an aerosol hairspray or aerosol mousse.