Use of benzotriazole derivatives of formula R1 is C1-C30alkyl C1-C5alkoxy C1-C5alkoxycarbonylC5-C7Cycloalkyl C6-C10aryl aralkyi R3 is hydrogen C1-C5alkyl C1-C5alkoxy halogen, preferably CI or hydroxy R4 and R5 are each independently of the other hydrogen or 1-C5alkyl m is 1 or 2 n is 0 or 1 if m = 1, R2 is hydrogen unsubstituted or phenyl-substituted C1-C12alkyl or C6-C10aryl if m = 2, R2 is the direct bond or -(CH2)p- and p is 1 to 3 for enhancing the photostability of cosmetic or dermatologic compositons comprising at least one further organic UV absorber.
