The invention pertains to a perfluoroelastomer composition comprising: at least one perfluoroelastomer comprising iodine and/or bromine atoms [perfluoroelastomer (A)]; from 0.5 to 5 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one bis-olefin [bis-olefin (OF)] having general formula (1) wherein R1, R2, R3, R4, R5 and R6, equal or different from each other, are H, a halogen, or a C1-C5 optionally halogenated group, possibly comprising one or more oxygen group; Z is a linear or branched C1-C18 optionally halogenated alkylene or cycloalkylene radical, optionally containing oxygen atoms, or a (per)fluoropolyoxyalkylene radical; from 0.1 to 3 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one organic peroxide; from 0.1 to 3 weight parts, per 100 parts by weight of said perfluoroelastomer (A), of at least one organic base [base (B)] selected from the group consisting of: (i) non-aromatic primary amines or amides complying with general formula (B1m) or (Bid): Rbm—[C(0)]t—NH2 (B1m) H2N—[C(O)]t′—Rdm—[C(O)]t″—NH2 (Bid) wherein: each of t, t′ and t″, equal to or different from each other and at each occurrence is zero or 1; Rbm is a monovalent hydrocarbon non-aromatic group having 12 to 30 carbon atoms; Rdm is a divalent hydrocarbon non-aromatic group having 6 to 30 carbon atoms; and (ii) cycloaliphatic secondary or tertiary amines complying with general formula (II) (B2m) or (B2d) wherein: Cy represents a divalent aliphatic group comprising at least 4 carbon atoms, optionally comprising one or more than one ethylenically unsaturated double bond, and optionally comprising one or more catenary nitrogen atoms, forming a cycle with the nitrogen atom which is connected thereto; Cy′ represent a trivalent aliphatic group comprising at least 5 carbon atoms, optionally comprising one or more than one ethylenically unsaturated double bond, and optionally comprising one or more catenary nitrogen atoms, forming a cycle with the nitrogen atom which is connected thereto.