  We report on the NuSTAR observations of two bright Seyfert 1 galaxies, namely
MCG +8-11-11 (100 ks) and NGC 6814 (150 ks). The main goal of these
observations was to investigate the Comptonization mechanisms acting in the
innermost regions of AGN which are believed to be responsible for the UV/X-ray
emission. The spectroscopic analysis of the NuSTAR spectra of these two sources
revealed that although they had different properties overall (black hole
masses, luminosity and Eddington ratios) they had very similar coronal
properties. Both presented a power law spectrum with a high-energy cutoff at
$\sim 150-200$ keV, a relativistically broadened Fe K$\alpha$ line and the
associated disk reflection component, plus a narrow iron line likely emitted in
Compton thin and distant matter. The intrinsic continuum was well described by
Comptonization models that show for MCG +8-11-11 a temperature of the coronal
plasma of kT$_{\rm e} \sim$ 60 keV and an extrapolated optical depth
$\tau$=1.8; for NGC 6814 the coronal temperature was kT$_{\rm e} \sim$ 45 keV
with an extrapolated optical depth of $\tau$=2.5. We compare and discuss these
values to some most common Comptonization models which aim at explaining the
energy production and stability of coronae in active galactic nuclei.
