  The four-dimensional helicity regularization scheme is often used in one-loop
QCD computations. It was recently argued in Ref. [1] that this scheme is
inconsistent beyond the one-loop order in perturbation theory. In this paper,
we clarify the reason for this inconsistency by studying the perturbative
expansion of the vector current correlator in one-flavor QED through three-loop
order. We develop a simple, practical way to fix the four-dimensional helicity
scheme using the idea of dimensional reconstruction, and demonstrate its
application in several illustrative examples.
