A wind turbine generator comprising a rotor, a stator and an air gap between a gap-delimiting region of the stator and a gap-delimiting region of the rotor; wherein the rotor and/or the stator are deformable under operational loads and configured in such a way that the air gap resulting from the presence of operational loads is more uniform than the air gap in the absence of operational loads. A method for optimizing an air gap between a gap-delimiting region of a stator and a gap-delimiting region of a rotor of a wind turbine generator, said rotor and/or said stator being deformable under operational loads and said optimization consisting in that the air gap resulting from the presence of the set of operational loads is more uniform than the air gap in the absence of the set of operational loads.