The present invention relates to a polyolefin composition comprising a crosslinkable polyolefin with hydrolysable silane groups and a silanol condensation catalyst, and (A) a compound containing one or more POm(OnR)(OoR)(OpR″) groups, wherein R, R′, and R″ are the same or different organic residues; m is 0 or 1; n, o, and p each are 0 or 1; and n+o+p=1 to 3; a master batch for a crosslinkable polyolefin composition comprising a polymer and a silanol condensation catalyst and component (A), a stabilized polyolefin containing cross-linked silane groups wherein cross-linking has been performed by the use of a silanol condensation catalyst, further comprising component (A), and to the use of component (A) for stabilizing a polyolefin composition comprising a crosslinkable polyolefin with hydrolysable silane groups and a silanol condensation catalyst. The polyolefin composition of the invention can be used for pipe, wire & cable, film, fiber and molding applications.