A wind turbine blade comprising a fairing with a rigid structural component (12) which forms the majority of the aerodynamic profile and a non-actively controllable elastically deformable trailing edge component (14) mounted on the structural component to complete the aerodynamic profile. The trailing edge component (14) is formed from a material having an elastic modulus in the range of 0.5 to 2.5 GPa such it will elastically buckle when loading on the trailing edge component exceeds a predetermined threshold. The structural component (12) comprises a unidirectional reinforcing layer adjacent to the trailing edge component with at least one layer of unidirectional fibers (26) extending in a substantially spanwise direction.