The rare decay h→Υγ has a very small rate in the
Standard Model, due to a strong cancellation between the direct and indirect
diagrams. Models with a changed hbb coupling can thus lead to a great
increase in this decay. Current limits on two Higgs doublet models still allow
for the possibility that the hbb coupling might have a sign opposite to the
Standard Model; the so-called "wrong-sign". We show how h→Υγ can be used to put limits on the wrong-sign solutions.Comment: 7 pages, 3 figure