In this paper we study consumption around the age of retirement. We consider a model where consumption and leisure are non-separable and retirement is endogenous. We consider the case where non-separabilities come from the existence of fixed costs to work. We show that the existence of unobserved heterogeneity related to these non-separabilities will lead to biases of the OLS estimators of structural parameters of demand systems conditioned on retirement. These estimates give bounds to the true fixed costs. We estimate the model with French data and compute the bounds of these structural parameters