The present invention relates to a polyolefin composition with increased resistance to degradation caused by ClO2-containing water and to a pipe or a fitting made of such a polyolefin composition. The polyolefin composition comprises a polyolefin base resin (A), an antioxidant (B) having a chroman-6-ol structure, and an antioxidant (C) having a phenolic structure and the molecule comprises at least one ester group. The present invention further relates to the use of the polyolefin composition for the production of a pipe or a fitting and to the use of the polyolefin composition for increasing the lifetime of a pipe or a fitting providing the polyolefin composition with resistance against degradation caused by contact with ClO2-containing water.
