In this talk we discuss 2d duality transformations in the classical AdS5 x S5 superstring and their effect on the integrable structure. We will see that combining T-duality along four directions in Poincare parametrization of AdS5 with a similar duality transformation on some of the fermionic variables maps the superstring action into itself. One implication is that, after duality, the superstring has a 'dual' superconformal symmetry group. Furthermore this dual superconformal symmetry can be seen as a consequence of the integrability of the superstring. This will also suggest that the dual superconformal charges correspond to non-local charges of the original model before T-duality.