Kudos to City Councilman Paul Vallone for refusing to let Mayor de Blasio get away with his unprecedented gift of taxpayer dollars to reward a single school-bus company — a firm run by a big donor and repped by Democratic fixer Harold Ickes.

But the council didn’t know the payouts would go to just one firm. That explains why the mayor never again asked lawmakers to OK the specific payout, instead burying it in his overall budget.

As the Citizens Budget Commission notes, it’s a terrible precedent — eroding the Bloomberg savings and undermining the integrity of the city’s procurement process by letting one firm win extra cash after bidding to provide a service for less.