  Combining constraints from microlensing and Lyman-$\alpha$ forest, we provide
a simple argument to show that large spatial clustering of stellar-mass
primordial black holes at the time of formation, such as the one induced by the
presence of large non-Gaussianities, is ruled out. Therefore, it is not
possible to evade existing constraints preventing stellar-mass primordial black
holes to be a dominant constituent of the dark matter by boosting their initial
clustering.
