We study pseudodifferential boundary value problems in the context of the Boutet de Monvel calculus or Green operators, with nonsmooth coefficients on smooth compact manifolds with boundary. In order to have a definition that is independent of the choice of (smooth) coordinates, one needs to prove that nonsmooth Green operators are invariant under smooth coordinate transformations. This is based on [1], a joint work with Prof. Helmut Abels from Universität Regensburg.