A method is disclosed for producing an improved polyvinyl chloride plastisol or organosol coating composition having improved adhesion to glass, metal or fabrics. The composition is obtained by adding to the plastisol or organosol from 0.1 to 2 weight percent of a devolatilized product of hydrolysis of an aminofunctional organotrialkoxysilane of the formula (RO).sub.3 SiCH.sub.2 CH.sub.2 CH.sub.2 NH--(CH.sub.2 CH.sub.2 NH).sub.x H wherein R is a monovalent alkyl radical of from 1 to 3 carbon atoms and x is zero or 1 and optionally a filler. The silane is hydrolyzed with at least 0 .5 moles of water per mole of silane. The compositions are stabilized in respect to viscosity by including 0.5 to 1.1 mole per mole of primary amino group in the hydrolyzed silane product of a compatible carboxylic acid boiling above 150.degree. C. at atmospheric pressure.