  We use direct $N$-body calculations to investigate the impact of primordial
mass segregation on the size scale and mass-loss rate of star clusters in a
galactic tidal field. We run a set of simulations of clusters with varying
degrees of primordial mass segregation at various galactocentric radii and show
that, in primordially segregated clusters, the early, impulsive mass-loss from
stellar evolution of the most massive stars in the innermost regions of the
cluster leads to a stronger expansion than for initially non-segregated
clusters. Therefore, models in stronger tidal fields dissolve faster due to an
enhanced flux of stars over the tidal boundary. Throughout their lifetimes, the
segregated clusters are more extended by a factor of about 2, suggesting that
(at least) some of the very extended globular clusters in the outer halo of the
Milky Way may have been born with primordial mass segregation. We finally
derive a relation between star-cluster dissolution time, $T_{diss}$, and
galactocentric radius, $R_G$, and show how it depends on the degree of
primordial mass segregation.
