Wet buffer tubes for use in fiber optic cables are made from a composition comprising in weight percent (wt %) based on the weight of the composition: (A) 22-49% polypropylene (PP), (B) 50-65% high density polyethylene (HDPE), (C) 7-12% compatibilizer comprising in wt % based on the weight of the compatibilizer: (1) 30-90% olefin block composite comprising ethylene-propylene (EP) copolymer, isotactic polypropylene (iPP), and an EP-iPP diblock polymer, and (2) 10-70% maleic anhydride grafted HDPE (MAH-g-HDPE); and (D) 0.05-5.0% nucleating agent.