An adhesive composition, including at least polymer containing silane groups, between 15 and 35 wt.-% of at least one polymeric plasiticzer, between 0.5 and 2.5 wt.-% of at least one monomeric or oligomeric aminofunctional alkoxysilane S1 with a nitrogen content of between 4.5 and 14.5 wt.-%, and between 0.5 and 2.5 wt.-% of at least one oligomeric aminofunctional alkoxysilane S2 with a nitrogen content of between 15 and 20 wt.-%. The adhesive composition is particularly suitable to seal or bond thermoplastic substrates, such as polyolefins or bituminous materials, and shows fast adhesion build-up and low volatile organic carbon (VOC).