Pigmented aqueous basecoat material comprises at least one alpha, omega-hydroxy-functionalized oligoester having an OH number of 25 to 95 mg KOH/g, a theoretical carbon-carbon double bond content of 0.5 to 2.5 mmol/g, a number-average molecular weight of 2500 to 6000 g/mol and a weight-average molecular weight of 15 000 to 30 000 g/mol, the alpha, omega-hydroxy-functionalized oligoester further comprising at least one partially or completely salified acid group, and the sum of the weight percentage fractions of all the alpha, omega-hydroxy-functionalized oligoesters being 0.5 to 10 wt %, based on the total solids fraction of the pigmented aqueous basecoat material. Also provided are a multicoat paint system, a method of producing a multicoat paint system, and use of the above-identified alpha, omega-hydroxy-functionalized oligoester in pigmented aqueous basecoat materials for the purpose of improving adhesion.