In this paper, I use a stochastic approach to model the effect that correlations between pension scheme assets and firm values should have on the premiums chargeable by the Pension Protection Fund. In particular, I look at the effect on the aggregate premium that should be charged considering a representative universe of companies and their pension schemes. I find that ignoring the correlations, even if the volatility of pension scheme assets is allowed for, leads to potentially serious underestimation of the aggregate premium due.