  Einstein-Gauss-Bonnet gravity coupled to a dynamical dilaton is examined from
the viewpoint of Einstein's equivalence principle. We point out that the usual
frame change that applies to the action without curvature correction does not
cure the problem of nonminimal couplings by the dynamical nature of a dilaton
field. Thus a modification of the Einstein frame is required. It is proposed
that the kinetic term of a dilaton should be brought to a canonical form, which
completely fixes the additional terms associated with the frame transformation.
