  It has been argued that a certain large $N$ matrix model may provide a
non-perturbative definition of $M$-theory. This model is the truncation to
$0+1$ dimensions of ten-dimensional supersymmetric Yang-Mills theory. It is
crucial to this identification that terms with four derivatives in the
effective action for the quantum mechanics should not be renormalized. We offer
a perturbative proof of this result.
