  In this article, we propose a physical condition to extend interior isotropic
solutions to anisotropic domains by gravitational decoupling in the framework
of the Minimal Geometric Deformation approach. In particular, it is found that
by using an expression reminiscent of the classical anisotropy factor, we can
close the decoupling system of equations and a new anisotropic solution can be
found. As an example, we extend the well--known Tolman IV.
