Although universal childcare has become an essential tool to support child development, few economic studies analyze its effects on non-cognitive skills and little is known about causal effects on these skills in the long run. In this paper we go beyond short run analyses and examine the long run effects of one additional year of universal childcare on students’ personality traits in adolescence. We focus on personality traits as part of their non-cognitive skills set and as important predictors of later educational achievements. As of 1996, a legal entitlement to universal childcare applied to children of three years and older in Germany. However, severe shortages in the former-West meant that many children could not get a childcare place and had to wait a full year until the next entry date. Using data from the National Educational Panel Study (NEPS) we estimate effects of one additional year of childcare by exploiting geographical variation in the timing of childcare entry arising from local supply constraints. We find that an earlier entry in universal childcare increases extroversion in adolescence, which has been shown to be associated with favorable labor market outcomes.