A length-adjustable steering shaft for a motor vehicle may include a hollow outer shaft with an unround inner cross section, in which an inner shaft is received in a torque-locked and axially movable manner. A profiled sleeve may be arranged between the inner shaft and the outer shaft, and the profiled sleeve may have a fastening portion connected to the inner shaft. The inner shaft may be configured at least in part as a hollow shaft that has an interior that is open towards the end that is inserted into the outer shaft. To reduce the outlay in terms of production and assembly, the fastening portion may extend from the end into the interior of the inner shaft and is connected to an inner surface of the interior.