A two-part polyurethane adhesive system comprising A) a polyisocyanate component that includes an aromatic polyisocyanate and B) a polyol component including B-1) from 20 to 75% by weight, based on the combined weights of components B-1) and B-2), of a polyether polyol or polyether polyol mixture, which polyether or polyether polyol mixture has an average of from 2 to 4 hydroxyl groups per molecule and a viscosity of up to 500 mPa•s at 25°C, B-2) from 25 to 80% by weight, based on the combined weights of components B-1) and B-2), of an aromatic polyester diol, B-3) from 0.1 to 3% by weight water, and B-4) from 0 to 15% by weight of isocyanate-reactive components other than components B-1), B-2) and B-3), further provided that (i) component A), component B) or both contains at least one catalyst for the reaction of isocyanate groups with hydroxyl group; (ii) the aromatic polyester diol is a reaction product of an aromatic dicarboxylic acid, aromatic dicarboxylic halide or aromatic dicarboxylic acid anhydride with diethylene glycol and a poly(ethylene glycol), has a hydroxyl equivalent weight of from 150 to 250 and has a viscosity of no greater than 2000 mPa•s at 25°C; and (iii) component A), component B) or both may contain a particulate mineral filler, in an amount up to 65% of the combined weight of components A) and B). A) a polyisocyanate component that includes an aromatic polyisocyanate and B) a polyol component including B-1) from 20 to 75% by weight, based on the combined weights of components B-1) and B-2), of a polyether polyol or polyether polyol mixture, which polyether or polyether polyol mixture has an average of from 2 to 4 hydroxyl groups per molecule and a viscosity of up to 500 mPa•s at 25°C, B-2) from 25 to 80% by weight, based on the combined weights of components B-1) and B-2), of an aromatic polyester diol, B-3) from 0.1 to 3% by weight water, and B-4) from 0 to 15% by weight of isocyanate-reactive components other than components B-1), B-2) and B-3), further provided that (i) component A), component B) or both contains at least one catalyst for the reaction of isocyanate groups with hydroxyl group; (ii) the aromatic polyester diol is a reaction product of an aromatic dicarboxylic acid, aromatic dicarboxylic halide or aromatic dicarboxylic acid anhydride with diethylene glycol and a poly(ethylene glycol), has a hydroxyl equivalent weight of from 150 to 250 and has a viscosity of no greater than 2000 mPa•s at 25°C; and (iii) component A), component B) or both may contain a particulate mineral filler, in an amount up to 65% of the combined weight of components A) and B). (i) component A), component B) or both contains at least one catalyst for the reaction of isocyanate groups with hydroxyl group; (ii) the aromatic polyester diol is a reaction product of an aromatic dicarboxylic acid, aromatic dicarboxylic halide or aromatic dicarboxylic acid anhydride with diethylene glycol and a poly(ethylene glycol), has a hydroxyl equivalent weight of from 150 to 250 and has a viscosity of no greater than 2000 mPa•s at 25°C; and (iii) component A), component B) or both may contain a particulate mineral filler, in an amount up to 65% of the combined weight of components A) and B).