Countries have demonstrated a tendency to switch their second pillar to defined contribution plans, increasing the market-sensitivity of pensions. This can lead to large differences across generations within a pension fund. In this paper we investigate how each cohort should invest if the goal is to prevent the existence of unlucky generations, without reducing overall pension levels. We find a closed-form solution for the optimal life-cycle investment that differs substantially from the classical CRRA investment and bears a strong resemblance to the 100−age rule of thumb. We show that this effectively reduces differences between consecutive cohorts.