  We study a No-Scale supergravity inflation model which has a non-minimal
deformation of the K\"ahler potential and a Wess-Zumino superpotential extended
by the inclusion of a Polonyi mass term. The non-minimal structure of the
K\"ahler potential is responsible for an inflexion point that can lead to the
production of gravitational waves at late stages of inflation, while the
Polonyi term breaks supersymmetry at the end of inflation, generating a
non-vanishing gravitino mass. After a thorough parameter space scan, we
identify promising points for gravitational wave production. We then study the
resulting gravitational wave energy density for this set of points, and we
observe that the gravitational waves should be observable in the next
generation of both space-based and ground-based interferometers. Finally, we
show how the presence of the Polonyi term can be used to further boost the
gravitational wave energy density, which is correlated with the gravitino mass.
