A fastening assembly for fastening a camshaft adjuster to a camshaft, having an input part that can be brought into driving engagement with a crankshaft, an output part that is non-rotationally connected to the camshaft, the output part being mounted rotationally adjustably with respect to the input part, and a control mechanism, by which a rotational angle position between the input and output parts can be adjusted. The output part is provided with a central axial opening penetrated by an end section of the camshaft. The end section has a thread-bearing thread section, which is screwed together with a tension nut acting on the output part such that the output part and the camshaft are axially loaded for the non-rotational connection thereof. To this end, the tension nut is elastically loaded in the axial direction or relieved in the axial direction.