A heat exchanger assembly comprising a frame (10) and a heat exchanger (20), wherein the heat exchanger (20) comprises a core of plates (21) stacked in a first direction, with edges (22) protruding along their outline, characterized in that the frame (10) comprises a retaining element (30) configured to engage plate edges (22) so that the retaining element (30) restricts movement of the heat exchanger (20) with respect to the frame (10) in the first direction, wherein the retaining element (30) comprises an elongated core (31) attached to the frame (10) and plurality of protrusions (32) protruding from this core (31), said protrusions (32) configured to protrude between plate edges (22).