  We consider constraints on the isoscalar S-wave pi-N scattering length a+
from pi-deuteron scattering, to third order in small momenta and pion masses in
chiral perturbation theory. To this order, the pi-deuteron scattering length is
determined by a+ together with three-body corrections that involve no
undetermined parameters. We extract a novel value for a combination of
dimension two low-energy constants which is in agreement with previous
determinations.
