  We show that a particular ``universal'' form for the soft-breaking couplings
in a softly broken $N=1$ supersymmetric gauge theory is renormalisation-group
invariant through two loops, provided we impose one simple condition on the
dimensionless couplings. The universal form for the trilinear couplings and
mass terms is identical to that found in popular derivations of the
soft-breaking terms from strings or supergravity.
