Recent policies aiming to prolong worklives have increased older males’ labor supply. Yet, little is known about their intergenerational e ects. Using unique Dutch administrative data covering three consecutive generations, this paper studies the impact of increased grandfathers’ labor supply following a reform in unemployment insurance for persons aged 57.5+ on grandchildren’s educational performance. We find that increased grandfathers’ labor supply increases grandchildren’s test scores in 6th grade. The e ect is driven by substitution of grandparents’ informal care by formal childcare.