A heat exchange system for a turbomachine includes a heat exchanger that has a support wall extending along a longitudinal direction L and a plurality of fins each extending along a radial direction from a radially external surface of the support wall. The heat exchanger further includes a first profiled wall arranged upstream from the fins and configured to guide and slow down the flow of air entering the heat exchanger through the fins. A second profiled wall is arranged downstream from the fins and configured to accelerate the flow of air leaving the heat exchanger. Each first and second profiled wall is attached to the support wall via support elements extending radially from the radially external surface.