  We present the results of a computation of the topological susceptibility in
the SU(3) Yang--Mills theory performed by employing the expression of the
topological charge density operator suggested by Neuberger's fermions. In the
continuum limit we find r_0^4 chi = 0.059(3), which corresponds to chi=(191 \pm
5 MeV)^4 if F_K is used to set the scale. Our result supports the
Witten--Veneziano explanation for the large mass of the eta'.
