  We revisit stellar energy-loss bounds on the Yukawa couplings $g_{\rm B,L}$
of baryophilic and leptophilic scalars $\phi$. The white-dwarf luminosity
function yields $g_{\rm B}\lesssim 7 \times 10^{-13}$ and $g_{\rm L}\lesssim 4
\times 10^{-16}$, based on bremsstrahlung from ${}^{12}{\rm C}$ and
${}^{16}{\rm O}$ collisions with electrons. In models with a Higgs portal, this
also implies a bound on the scalar-Higgs mixing angle $\sin \theta \lesssim 2
\times 10^{-10}$. Our new bounds apply for $m_\phi\lesssim {\rm 1~keV}$ and are
among the most restrictive ones, whereas for $m_\phi\lesssim 0.5\,{\rm eV}$
long-range force measurements dominate. Besides a detailed calculation of the
bremsstrahlung rate for degenerate and semi-relativistic electrons, we prove
with a simple argument that non-relativistic bremsstrahlung by the heavy
partner is suppressed relative to that by the light one by their squared-mass
ratio. This large reduction was overlooked in previous much stronger bounds on
$g_{\rm B}$. In an Appendix, we provide fitting formulas (few percent
precision) for the bremsstrahlung emission of baryophilic and leptophilic
scalars as well as axions for white-dwarf conditions, i.e., degenerate,
semi-relativistic electrons and ion-ion correlations in the ``liquid'' phase.
