  The Debye shielding of a charge immersed in a flowing plasma is an old
classic problem in plasma physics. It has been given renewed attention in the
last two decades in view of experiments with complex plasmas, where charged
dust particles are often levitated in a region with strong ion flow. Efforts to
describe the shielding of the dust particles in such conditions have been
focused on the homogeneous plasma approximation, which ignores the substantial
inhomogeneity of the levitation region. We address the role of the plasma
inhomogeneity by rigorously calculating the point charge potential in the
collisionless Bohm sheath. We demonstrate that the inhomogeneity can
dramatically modify the wake, making it non-oscillatory and weaker.
