During the last 30 years, women started giving birth at higher ages. While in 1990 the average age at first birth was 26, in 2019 this number was already 29. Given this trend, we ask whether the decision to postpone fertility helped to close the gender wage gap. Our results show that yes. Postponing fertility by a year lead to a fall in the gender wage gap by 2 percent, or approximately 12% of the average gap.