People v. Whitfield, 217 Ill. 2d 177, 840 N.E.2d 658, 298 Ill. Dec. 545 (2005), is instructive in resolving whether defendant has made a substantial showing that his constitutional rights were violated when the trial court failed to advise him about mandatory supervised release (MSR). In Whitfield, the defendant entered a fully negotiated guilty plea in exchange for concurrent 25-year and 6-year prison terms. Whitfield, 217 Ill. 2d at 179, 840 N.E.2d at 661. At no time during the plea proceedings did the prosecutor or the court advise the defendant that he would be subject to a three-year period of MSR following his release from prison. Whitfield, 217 Ill. 2d at 180, 840 N.E.2d at 661. The sentencing order did not reference the three-year MSR term required by law. Whitfield, 217 Ill. 2d at 180 n.1, 840 N.E.2d at 661 n.1. The defendant did not file a direct appeal. Whitfield, 217 Ill. 2d at 180, 840 N.E.2d at 661. Later, while serving his prison sentence, the defendant became aware that a 3-year term of MSR had been added to his 25-year sentence by operation of law. Whitfield, 217 Ill. 2d at 180, 840 N.E.2d at 661. The defendant filed a motion for relief from judgment that the court treated as a postconviction petition. The defendant contended that his fourteenth amendment (U.S. Const., amend. XIV) due-process rights were violated because he was never advised of the MSR that "had been added to his negotiated sentence and resulted in a 'more onerous' sentence than the one he had agreed to when he pled guilty." Whitfield, 217 Ill. 2d at 180, 840 N.E.2d at 661. The defendant did not request that his plea be withdrawn but sought to enforce the terms of the plea agreement by reducing his 25-year prison term by the length of the MSR term. Whitfield, 217 Ill. 2d at 180-81, 840 N.E.2d at 661. The trial court denied the petition and the appellate court affirmed. Whitfield, 217 Ill. 2d at 181-82, 840 N.E.2d at 662. The Whitfield court stated that a defendant's due-process rights may be violated where the defendant did not receive the "benefit of the bargain" of his plea agreement with the State. Whitfield, 217 Ill. 2d at 186, 840 N.E.2d at 664. The defendant in Whitfield argued that the trial court was required under Rule 402 (177 Ill. 2d R. 402) to admonish him on the record of the statutorily required MSR term. Whitfield, 217 Ill. 2d at 186, 840 N.E.2d at 664. The defendant argued that because the court failed to admonish the defendant of the statutorily required MSR term, the defendant's plea agreement included only the prison sentence and not the additional MSR term. Whitfield, 217 Ill. 2d at 186, 840 N.E.2d at 665. Under those circumstances, the Whitfield court concluded that adding the statutorily required three-year MSR term to defendant's negotiated 25-year sentence amounts to an unilateral modification and breach of the plea agreement by the State, "'inconsistent with constitutional concerns of fundamental fairness.'" Whitfield 217 Ill. 2d at 190, 840 N.E.2d at 667. The Whitfield court concluded: "Although substantial compliance with Rule 402 is sufficient to establish due process citations, and an imperfect admonishment is not reversible error unless real justice has been denied or the defendant has been prejudiced by the inadequate admonishment citation, there is no substantial compliance with Rule 402 and due process is violated when a defendant pleads guilty in exchange for a specific sentence and the trial court fails to advise the defendant, prior to accepting his plea, that an MSR term will be added to that sentence." Whitfield, 217 Ill. 2d at 195, 840 N.E.2d at 669. The Whitfield court held that the petitioner established a substantial violation of his constitutional rights because he pleaded guilty in exchange for a specific sentence, and the addition of the MSR term resulted in a sentence "more onerous than the one defendant agreed to at the time of the plea hearing." Whitfield, 217 Ill. 2d at 195, 840 N.E.2d at 669. The supreme court further determined that, although the defendant was entitled to the benefit of his bargain, the law did not permit the term of MSR to be stricken from the defendant's sentence. Whitfield, 217 Ill. 2d at 202-03, 840 N.E.2d at 673. Accordingly, the court held that the appropriate remedy, which would approximate the defendant's bargain with the State, was to reduce the defendant's prison term by a period equal in length to the MSR term. Whitfield, 217 Ill. 2d at 203, 840 N.E.2d at 674. In Whitfield, the court reduced the defendant's 25-year prison term by 3 years so that the sum of the 25-year prison term to which he had agreed in his plea agreement and the MSR term equaled 25 years. Whitfield, 217 Ill. 2d at 203, 840 N.E.2d at 674.