delivered the opinion of the court:
Defendant, Beverly L. Coleman, was found guilty in a bench trial of bringing contraband into a penal institution (Ill. Rev. Stat. 1981, ch. 38, par. 31A — 1(a)(3)), unlawful possession of a controlled substance (less than 30 grams of a substance containing pentazocine) (Ill. Rev. Stat. 1981, ch. 56V2, par. 1402(b)), and unlawful possession of cannabis (less than 2.5 grams of a substance containing cannabis) (Ill. Rev. Stat. 1981, ch. 56V2, par. 704(a)). She was subsequently sentenced to concurrent two-year terms of imprisonment for the offenses of bringing contraband into a penal institution and unlawful possession of a controlled substance. No sentence was entered on the misdemeanor offense of unlawful possession of a substance containing cannabis.
The sole issue raised on appeal is whether defendant’s conviction for bringing contraband into a penal institution is void because the statutory subsection under which she was convicted was unconstitutionally enacted after action by the Governor, which purportedly exceeded the scope of his amendatory veto powers. In this regard she contends that subsection (3) of section 31 A — 1(a), under which she was convicted, was added in its entirety by the Governor in his amenda-tory veto letter to the Illinois Senate and was subsequently adopted by the General Assembly. The State maintains this issue has been waived.
*853 Defendant failed to raise the issue of the constitutionality of this statute and the procedures of its enactment in the trial court. It is fundamental that the failure to raise the issue of a statute’s constitutionality in the trial court is a waiver of that issue on review. People v. Amerman (1971), 50 Ill. 2d 196, 279 N.E.2d 353; People v. Luckey (1969), 42 Ill. 2d 115, 245 N.E.2d 769; People v. Denby (1981), 102 Ill. App. 3d 1141, 1146, 430 N.E.2d 507; People v. Lenninger (1980), 88 Ill. App. 3d 801, 807, 410 N.E.2d 1157; People v. Jones (1980), 86 Ill. App. 3d 253, 258, 408 N.E.2d 79; see also People v. Myers (1981), 85 Ill. 2d 281, 290-91, 426 N.E.2d 535.
Defendant contends, however, that conviction under a void statute may be attacked at any time, and cites three recent decisions of our supreme court, People v. McCarty (1983), 94 Ill. 2d 28, 445 N.E.2d 298, People v. Wagner (1982), 89 Ill. 2d 308, 433 N.E.2d 267, and In re T.E. (1981), 85 Ill. 2d 326, 423 N.E.2d 910, as support for this argument.
While we believe, upon analysis of these decisions, that some of the language in those opinions arguably is helpful to the defendant’s contention, these cases are not directly apposite to the instant case, and we perceive no indication in those opinions that the waiver rule articulated in People v. Amerman (1971), 50 Ill. 2d 196, 279 N.E.2d 353, has been overruled. In McCarty and In re T.E., a constitutional challenge not raised at the trial level was allowed because the sentence or probation order was void. In Wagner, the constitutionality of the statute, while not presented in a post-trial motion was raised in a pretrial motion, and a subsequent decision, while the appeal in Wagner was pending, was rendered which held a similar statute unconstitutional.
In the case at bar, the language of the statute itself is not challenged, but the constitutional defect claimed is a procedural infirmity in its enactment. The only indication we have of the legislative and executive process in the enactment of this law is a copy of a letter to the members of the Illinois Senate signed by Governor Thompson, contained in appendix B to defendant’s brief, which states, inter alia, that under article IV, section 9(e) of the 1970 Illinois Constitution, he is returning Senate Bill 624 with specific recommendations for change, and if so changed, the bill would have his approval. Other than this copy of Governor Thompson’s purported veto letter, the defendant has failed to present to this court, or more properly to the trial court, any authenticated documents which contain the legislative and executive process which he claims create a constitutional defect in the enactment of the law. Such proofs, and any possible contrary evi*854dence, ought to be first presented in the trial court.
Although the waiver rule is a limitation on the parties and not the courts, and a reviewing court may ignore the waiver in the interest of substantial justice (People v. Winston (1982), 106 Ill. App. 3d 673, 688, 435 N.E.2d 1327), we are not so compelled under the circumstances described above and from our review of the nature of the claimed constitutional question.
The judgment below is affirmed.
Affirmed.
UNVERZAGT and LINDBERG, JJ., concur.