  The MARI direct geometry time-of-flight neutron spectrometer at ISIS has been
upgraded with an $m=3$ supermirror guide and new detector electronics. This has
resulted in a flux gain of ${\approx}6{\times}$ at $\lambda=1.8$ {\AA}, and
improvements on discriminating electrical noise, allowing MARI to continue to
deliver a high quality science program well into its fourth decade of life.
