The present invention relates to a heat-crosslinkable adhesive composition comprising: —from 20% to 84% by weight of composition (A); —from 15% to 79% by weight of a compatible tackifying resin (B), —from 0.01% to 5% by weight of a crosslinking catalyst (C). The invention also relates to a self-adhesive item obtained by preheating said composition, coating on a support layer, then crosslinking by heating.