A numerical model of the stratospheric sudden warming is used to test the observationally based suggestion that the warming is sensitive to the phase of the quasi-biennial oscillation in the equatorial lower-stratospheric zonal wind field. Some tests show essentially no sensitivity, while in others small differences are noted between integrations representing the east and west phases of the oscillation. The nature of such differences as we find appears to support observational results. The numerical results neither contradict nor strongly support the observations, but may suggest that over the entire winter period differences may be sufficient in a cumulative sense to give the appearance of a sensitivity in the warming.