This paper investigates the e ect of the 2003 French pension reform on hiring, ring and employment rates among older workers. This reform increased the mandatory retirement age and simultaneously it set a tax levied on early retirement windows payed by rms to their older workers, to encourage them to leave their job early. We use a matching model with endogenous job destruction extended to account for a mandatory retirement age and we calibrate the model with data drawn from the French Labor Force Surveys for the years 2001 and 2002. We show that in the case of a high tax rate, delaying retirement raises job separation rates, which partially o sets its positive e ect on job nding rates. Consequently, the combination of an increase in the retirement age and a taxation on early retirement windows may have perverse e ects on the employment rate among older workers.