A backplate for a door actuator includes at least one first mounting element and a second mounting element, wherein one of the two mounting elements is formed for fastening to a mounting surface, in particular door, casing or wall, and the other mounting element is formed for receiving the door actuator. The backplate also includes, at least one connecting assembly, which in a retaining position, keeps the two mounting elements together and, in a release position, does not keep the two mounting elements together, and at least one shape memory assembly with a shape memory element made from shape memory material, wherein, upon thermal activation, the shape memory assembly moves the connecting assembly to the release position.