  If the disappearance of the broad emission lines observed in changing-look
quasars were caused by the obscuration of the quasar core through moving dust
clouds in the torus, high linear polarization typical of type 2 quasars would
be expected. We measured the polarization of the changing-look quasar
J1011+5442 in which the broad emission lines have disappeared between 2003 and
2015. We found a polarization degree compatible with null polarization. This
measurement suggests that the observed change of look is not due to a change of
obscuration hiding the continuum source and the broad line region, and that the
quasar is seen close to the system axis. Our results thus support the idea that
the vanishing of the broad emission lines in J1011+5442 is due to an intrinsic
dimming of the ionizing continuum source that is most likely caused by a rapid
decrease in the rate of accretion onto the supermassive black hole.
