Abstract: The invention relates to a device for adjusting the configuration of a modular prosthetic leg, the leg prosthesis having a foot section, a lower leg section and a knee joint, and the knee joint being disposed via a lower part on the lower leg section and an upper part being joined in an articulated manner with the lower part, having a frame and at least one fixing device disposed on the frame for fixing the foot section and the knee joint, an adjustable bracket for a thigh shaft being attached to the frame and holding a thigh shaft that is attached to the upper part of the prosthesis in its orientation with respect to the knee joint.