  We analyse type IIA Calabi-Yau orientifolds with backgroud fluxes, taking
into account the effect of perturbative $\alpha'$-corrections. In particular,
we consider the $\alpha'$-corrections that modify the metrics in the K\"ahler
sector of the compactification. As it has been argued in the literature,
including such $\alpha'$-corrections allows to construct the mirror duals of
type IIB Calabi-Yau flux compactifications, in which the effect of flux
backreaction is under control. We compute the $\alpha'$-corrected scalar
potential generated by the presence of RR and NS fluxes, and reformulate it as
a bilinear of the flux-axion polynomials invariant under the discrete shift
symmetries of the compactification. The use of such invariants allows to
express in a compact and simple manner the conditions for Minkowski and AdS
flux vacua, and to extract the effect of $\alpha'$-corrections on them.
