The invention relates to a process for the preparation of an oxygen barrier film having an oxygen barrier layer and a treated substrate, comprising the steps of: a) subjecting a polyolefin substrate to a surface treatment to obtain the treated substrate wherein the surface under the parts of the curves corresponding to the C—O, C—N and C═O groups is at least 10% based on the total surface under the curve as obtained by X-ray photoelectron spectroscopy (XPS), b) applying an aqueous or hydroalcoholic coating composition comprising 0.1 to 25 wt % of polyvinyl alcohol, 0.1 to 30 wt % of a metal alkoxide and optional silicate minerals on the treated substrate obtained by step a) and c) drying the coating composition to obtain the oxygen barrier layer resulting in the oxygen barrier film, wherein the amount of the optional silicate minerals in the coating composition is less than 10 parts by weight per 100 parts by weight of the polyvinyl alcohol in the coating composition.