The invention relates to an adhesive system comprising (a) an etherified amino resin, (b) a polymer prepared from one or more ethylenically unsaturated monomers, (c) a curing agent, and (d) a polyvinyl alcohol and the use thereof for gluing wood based products. The invention also relates to a hardener composition for gluing systems of the amino resin type comprising, (b) a polymer prepared from one or more ethylenically unsaturated monomers, said polymer containing post-crosslinking groups, (c) a carboxylic acid and (d) a polyvinyl alcohol and the use thereof for formulating an adhesive system. The invention further relates to a method of application of the adhesive system or the hardener composition onto the surface to be glued.