  We investigate the possibility of extending the "partially massless" symmetry
of a spin-2 field in de Sitter to nonlinear order. To do so, we impose a
closure condition on the symmetry transformations. This requirement imposes
strong constraints on the form of the nonlinear symmetry while making only
minimal assumptions about the form of the nonlinear partially massless action.
We find a unique nonlinear extension of the free partially massless symmetry.
However, we show that no consistent Lagrangian that contains at most two
derivatives of the fields can realize this symmetry.
