Method for making a film that comprises microfibrillated cellulose, wherein the film has low OTR values and especially suitable for a tropical environment. The method comprising the steps of providing a suspension comprising microfibrillated cellulose (MFC), forming a film from said suspension, wherein the film having a solid content above 40%, preferably above 50%, treating the film with flame or plasma treatment, such that a surface activation takes place on the film, and cooling the film, wherein the surface of the film having a decreased OTR value and a high moisture resistance.