A composition, article, and method for increasing the hydrolytic stability of a polymer; wherein a composition includes: a polymer comprising functional groups having hydrolyzable bonds; a carbodiimide compound; and a weak base (or hindered amine); wherein the carbodiimide compound and weak base (or hindered amine) are used in amounts effective to decrease the rate and/or extent of hydrolytic degradation of the polymer relative to either used alone in the same amount with the polymer.