  The pure spinor superstring in a type II curved background is considered. In
order to define reparametrization ghosts, non-minimal pure spinor variables
have to be present in the formalism. The BRST transformations of the
non-minimal variables are obtained. It is found that the BRST transformations
of a set of world-sheet variables have the form of the corresponding
transformations in flat spacetime, up to a field-dependent Lorentz rotation.
This simplify the construction of the reparametrization $b$ ghosts.
