The present disclosure relates to an acid-curable composition, comprising: a) a base component comprising a cationically self-curable oligomeric compound; b) a curing system for the cationically self-curable oligomeric compound, which comprises: i. an ionogenic compound comprising an anion and ammonium as a cation; and ii. water. According to another aspect, the present disclosure is directed to a curing system suitable for an acid-curable composition comprising a cationically self-curable oligomeric compound. According to still another aspect, the present disclosure relates to a method of manufacturing an acid-curable composition. In yet another aspect, the disclosure relates to the use of an acid-curable composition for industrial applications, in particular for thermal management applications in the automotive industry.