A composite stiffener for a stiffener reinforced panel is disclosed. The stiffener has a longitudinal direction and a run-out region which terminates at an end of the stiffener. The stiffener also has a constant section region inboard of the run-out region in the longitudinal direction and having a constant cross section transverse to the longitudinal direction with a crown between adjacent foot portions. The run-out region has a changing cross section transverse to the longitudinal direction with a crown between adjacent foot portions and the crown reduces in height towards the end of the stiffener forming a ramp. The composite stiffener includes a number of blankets of non-crimp fabric layers.