  The existence of stable magnetic configurations in white dwarfs, neutron
stars and various non-convective stellar {regions} is now well recognized. It
has recently been shown numerically that various families of equilibria,
including axisymmetric mixed poloidal-toroidal configurations, are stable. Here
we test the stability of an analytically-derived non force-free magnetic
equilibrium, using three-dimensional magnetohydrodynamic simulations: the mixed
configuration is compared with the dynamical evolution of its purely poloidal
and purely toroidal components, both known to be unstable. The mixed
equilibrium shows no sign of instability under white noise perturbations. {This
configuration therefore provides a good description of magnetic equilibrium
topology inside non-convective stellar objects and will be useful to initialize
magneto-rotational transport in stellar evolution codes.
