Where the trial court imposes a restitution fine under Penal Code section 1202.4, subdivision (b), but omits or imposes an erroneous parole revocation fine, appellate courts may correct this error even though the People failed to object at sentencing. Here, the trial court imposed a $5,000 restitution fine, and a $200 parole revocation fine. The Court of Appeals properly corrected the erroneous imposition of the parole revocation fine, despite the People’s failure to object, by increasing it to $5,000. Because appellant failed to argue that the imposition of the $5,000 restitution fine was improper, there were no grounds for contesting the amount of the parole revocation fine. This error was so obvious and so easily fixable that correction of these errors in the absence of an objection at sentencing will not unduly burden the courts or the parties. Justice Mosk concurred separately.