Abstract: Supersymmetric compactifications of string and M-theory have been intensely studied over the last years. One of the major questions in this context is the appearance of perturbative and non-perturbative string corrections. In this talk I will explain that many of these compactifications admit additional, spontaneously broken supercharges that can explain the vanishing of certain perturbative string corrections and lead to conjectures for the vanishing of certain non-perturbative corrections. I will give concrete examples and show how they are related by dualities.