  We study, following Bertini et al. \cite{Bertini:2011ga}, the hidden
conformal symmetry of the massless Klein-Gordon equation in the background of
the general, charged, spherically symmetric, static black-hole solution of a
class of d-dimensional Lagrangians which includes the relevant parts of the
bosonic Lagrangian of any ungauged supergravity. We find that a hidden
SL(2,\mathbb{R}) symmetry appears at the near event and Cauchy-horizon limit.
