  We study the variation of the optical polarization angle in the blazar OJ287
and compare it with the precessing binary black hole model with a 'live'
accretion disk. First, a model of the variation of the jet direction is
calculated, and the main parameters of the model are fixed by the long term
optical brightness evolution. Then this model is compared with the variation of
the parsec scale radio jet position angle in the sky. Finally, the variation of
the polarization angle is calculated using the same model, but using a magnetic
field configuration which is at a constant angle relative to the optical jet.
It is found that the model fits the data reasonably well if the field is almost
parallel to the jet axis. This may imply a steady magnetic field geometry, such
as a large-scale helical field.
