Agent for treating fibers containing keratin, particularly 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 independently=H or methyl; X1 and X2 independently=O or NH, A1 and A2 independently=ethan-1,2-diyl, propan-1,3-diyl or butan-1,4-diyl, R2, R3, R5 and R6 independently=(C1-C4) alkyl, R7═(C8-C30) alkyl, and (b) at least one film-forming anionic and/or stabilizing anionic polymer comprising at least one structural unit of formula (V) and at least one structural unit of formula (VI), wherein R8 and R9 independently=hydrogen or methyl, with the proviso that R8 and R9 are not simultaneously methyl, R10=hydrogen or methyl, R11=carbamoyl, linear or branched (C4 to C12) alkylaminocarbonyl, linear or branched (C4 to C12) alkylaminoethyl-aminocarbonyl, linear or branched (C4 to C12) alkylaminopropyl-aminocarbonyl, linear or branched (C4 to C12) alkyloxycarbonyl, linear or branched (C4 to C12) alkylaminoethyloxycarbonyl, linear or branched (C4 to C12) alkylaminopropyloxycarbonyl, linear or branched (C2 to C12) acyloxy, A3=hydroxyl or an organic group having at least one sulfonic acid group that bonds through an oxygen atom or an NH group to the structural fragment. The invention also relates to use of agents for temporarily styling hair and for haircare, particularly as aerosol hairspray or aerosol hair mousse.