In a purchase agreement about shares of a limited company, the clause whereby the seller undertakes to indemnify the purchaser against contingent liabilities in the company's assets relates to an ancillary service and therefore does not fall within the scope of the warranty under Article 1497 of the Italian Civil Code. Therefore, the buyer's right to compensation based on the said clause is not subject to the one-year limitation period of Articles 1495 and 1497 of the Civil Code, but to the ordinary ten-year limitation period.