Photosensitive compositions comprising (A) an alkali soluble compound; (B) at least one compound, of formula I or II wherein R1 inter alia is C4-C9cycloalkanoyl, C3-C12alkenoyl, or benzoyl which is unsubstituted or substituted; Ar1 is either C6-C20aryl or C6-C20aryloyl each of which is unsubstituted or substituted; x is 2 or 3; M1 when x is 2, inter alia is a group phenylene or naphthylene, each of which optionally is substituted i.a. by OR3, SR4 or NR5R6; or M1, when x is 3, is a trivalent group, optionally substituted; R3 is for example hydrogen or C1-C12alkyl; C2-C6alkyl which is for example substituted by —OH, —SH, —CN, C3-C6alkenoxy, or —OCH2CH2CN; R4 is for example hydrogen, C1-C12alkyl, C3-C12alkenyl, cyclohexyl, or phenyl which is unsubstituted or substituted; R5 and R6 independently of each other inter alia are hydrogen, C1-C12alkyl, C2-C4hydroxyalkyl, C2-C10alkoxyalkyl, C3-C5alkenyl, C3-C8cycloalkyl, phenyl-C1-C3alkyl, C1-C4alkanoyl, C3-C6alkenoyl, benzoyl or phenyl which is unsubstituted or substituted; and (C) a photopolymerizable compound; exhibit an unexpectedly good performance, in particular in photoresist technology.