A plate heat exchanger, comprising: a plurality of heat exchanger plates which are stacked and permanently connected to form a plate package that defines first and second fluid paths for a first medium and a second medium, respectively, separated by said heat exchanger plates, said plate package defining a surrounding external wall that extends in an axial direction between first and second axial ends, an end plate (21; 24) permanently connected to one of the first and second axial ends so as to provide an end surface that extends between first and second longitudinal ends in a lateral plane which is orthogonal to the axial direction, and two mounting plates permanently connected to a respective surface portion of the end surface at the first longitudinal end and the second longitudinal end, respectively, such that the mounting plates are spaced from each other in a longitudinal direction on the end surface, wherein the respective mounting plate comprises opposing flat engagement surfaces (12, 13) connected by an edge portion that extends along the perimeter of the mounting plate, wherein the respective mounting plate is arranged with one of its engagement surfaces (12, 13) permanently connected to the end surface, such that the perimeter of the mounting plate partially extends beyond the surrounding external wall, so as to define a mounting flange, characterized in that the respective mounting plate partially extends across the end surface in contact with the same within the perimeter of the surrounding external wall, and the perimeter of the mounting plate comprises two concave portions as seen in a normal direction to the end surface, the concave portions being located to intersect the surrounding external wall at a respective intersection point. a plurality of heat exchanger plates which are stacked and permanently connected to form a plate package that defines first and second fluid paths for a first medium and a second medium, respectively, separated by said heat exchanger plates, said plate package defining a surrounding external wall that extends in an axial direction between first and second axial ends, an end plate (21; 24) permanently connected to one of the first and second axial ends so as to provide an end surface that extends between first and second longitudinal ends in a lateral plane which is orthogonal to the axial direction, and two mounting plates permanently connected to a respective surface portion of the end surface at the first longitudinal end and the second longitudinal end, respectively, such that the mounting plates are spaced from each other in a longitudinal direction on the end surface, wherein the respective mounting plate comprises opposing flat engagement surfaces (12, 13) connected by an edge portion that extends along the perimeter of the mounting plate, wherein the respective mounting plate is arranged with one of its engagement surfaces (12, 13) permanently connected to the end surface, such that the perimeter of the mounting plate partially extends beyond the surrounding external wall, so as to define a mounting flange, characterized in that the respective mounting plate partially extends across the end surface in contact with the same within the perimeter of the surrounding external wall, and the perimeter of the mounting plate comprises two concave portions as seen in a normal direction to the end surface, the concave portions being located to intersect the surrounding external wall at a respective intersection point.