The aim of this work is to propose a Gurson-type model for ductile porous solids exhibiting isotropic and kinematic hardening. The derivation is based on a ``sequential limit-analysis" of a hollow sphere made of a rigid-hardenable material. The heterogeneity of hardening is accounted for by discretizing the cell into a finite number of spherical layers in which the quantities characterizing hardening are considered as homogeneous. The model is assessed through comparison of its predictions with the results of some micromechanical finite element simulations of the same cell. The numerical and theoretical overall yield loci are compared for given distributions of isotropic and kinematic pre-hardening. A very good agreement between model predictions and numerical results is found in both cases.