  We consider the effect of the R^4 term in type IIA string theory on the
supergravity background dual to N_c D4 branes compactified on a circle with
supersymmetry breaking boundary conditions. We study the dynamics of D8 branes
in this perturbed geometry in the probe approximation. This leads to an
analysis of higher derivative corrections in holographic QCD beyond the
supergravity approximation. We make a rough estimate of the corrections to the
masses of some of the lightest (axial) vector mesons. The corrections are
suppressed by a factor of (g_{YM}^2 N_c)^{-3} compared to their supergravity
values. We find that the masses of these mesons increase from their
supergravity values.
