  We investigate quantum correlations between successive steps of black hole
evaporation and investigate whether they might resolve the black hole
information paradox. 'Small' corrections in various models were shown to be
unable to restore unitarity. We study a toy qubit model of evaporation that
allows small quantum correlations between successive steps and reaffirm
previous results. Then, we relax the 'smallness' condition and find a
nontrivial upper and lower bound on the entanglement entropy change during the
evaporation process. This gives a quantitative measure of the size of the
correction needed to restore unitarity. We find that these entanglement entropy
bounds lead to a significant deviation from the expected Page curve.
