# Does potential energy increase inertial mass of system?

For example, we have a ball with mass m lying on the Earth. Then we lift it to a height h. So, now system Earth-ball have potential energy $$E_p = mgh$$. From Mass–energy equivalence system got $$mass = \frac{E_p}{c^2}$$. Does it mean that potential energy increased inertial mass of system and it's harder to accelerate that system, or potential energy just increased rest mass of system Earth-ball?