  I here discuss the THDMa, a type II two Higgs doublet model that is enhanced
by an additional pseudoscalar which serves as a portal to the dark matter
sector containing a fermionic dark matter andidate. I present a recent scan of
the models parameter space where all parameters are allowed to float freely,
and discuss prospects for this model at future $e^+e^-$ colliders for cases
that are not covered in standard THDM searches.
