Abstract: Toric varieties are complex varieties with a torus action that are defined by convex-geometric objects called fans. Twenty years ago, Buchstaber and Panov proposed a formula for the cohomology ring of a smooth toric variety in terms of a torsion product involving the Stanley-Reisner ring given by the fan. We show that their formula gives the correct cup product if 2 is invertible in the chosen coefficient ring, but not in general. We rectify this by defining an explicit deformation of the canonical multiplication on the torsion product. Along the way, we will give important advice to grad students.