A silane-functional polyester of formula (I): wherein Y is an n-valent residue of a polyester P which is solid at room temperature and terminated by hydroxy groups, after removal of n hydroxy groups; R1 is a linear or branched, monovalent carbon residue having 1 to 12 carbon atoms, optionally having one or more C—C multiple bonds and/or having optionally cycloaliphatic and/or aromatic portions; R2 is an acyl residue or a linear or branched, monovalent hydrocarbon residue having 1 to 12 carbon atoms, optionally having one or more C—C multiple bonds and/or having optionally cycloaliphatic and/or aromatic portions; R3 is a linear or branched, divalent hydrocarbon residue having 1 to 12 carbon atoms, optionally having cyclic and/or aromatic portions, and optionally having one or more heteroatoms; the index a has a value of 0, 1 or 2; and the index n has a value of 1 to 3.