Opinion by Judge RYMER; Dissent by Judge THOMAS
RYMER, Circuit Judge:
Felix Severino appeals his sentence for one count of conspiracy to distribute a controlled substance in violation of 21 U.S.C. § 846, and seven counts of distributing a controlled substance in violation of 21 U.S.C. § 841(a)(1). The district court sentenced him to a mandatory minimum term of 120 months as a recidivist under 21 U.S.C. § 841(b)(1)(B). Severino argues that his sentence was improperly enhanced without the due process required by 21 U.S.C. § 851 because the information was defectively filed and served. We disagree, and affirm.
I
Severino and 17 others were charged in a Superseding Indictment filed December 13, 1995 with conspiracy to distribute cocaine and related charges of distribution and possession in violation of 21 U.S.C. §§ 846 and 841(a)(1). He and the United States entered into a written plea agreement under Fed.R.Crim.P. 11(e)(1)(C) on January 9, 1996. Severino admitted guilt on the eight drug counts for which he had been indicted. Among other things, the agreement provides that “[a]ny prior record including any drug convictions will be brought to the attention of the court”; and it acknowledges that “[i]f a defendant has a prior felony drug conviction the penalties are from 10 years to life imprisonment, a maximum fine of $4,000,000, and at least 8 years of supervised release.” The agreement also waives the right to appeal or collaterally attack Severino’s conviction or sentence on any ground “unless the court imposes a sentence in excess of the statutory maximum or a sentence that is contrary to the sentencing guidelines or a sentence that violates this plea agreement.”
A plea hearing was held on January 9. As it turned out, Severino, his counsel and the district judge were physically present in court in Anchorage; the Assistant United States Attorney (AUSA) was in Fairbanks, and participated by telephone. As the court was discussing possible guidelines calculations during the plea colloquy, Severino’s counsel stated: “... we may not know the extent of his criminal history, but we do know one thing.... He has a prior drug conviction back East ... So that — because of the amount, of course you’ll kick up to that mandatory 10 years.” The following dialogue then occurred:
THE COURT: Okay. So he is going into this with eyes open and facing a mandatory minimum of 10 years—
MR. DAYAN [Severino’s counsel]: Yes, Your Honor.
THE COURT: —120 months?
MR. DAYAN: Yes, Your Honor.
THE COURT: Is that correct, Mr. Severino? You were aware of that?
THE DEFENDANT: Yes, sir.
THE COURT: Okay.
MR. DAYAN: Of course, we’ll ask the Government be — you know, they’ll be put to the proof of the conviction, but I have—
THE COURT: Sure.
MR. DAYAN: — no doubt they can do it.
[853]*853THE COURT: Okay. And you’ve discussed that with Mr. Severino. He understands how you would go about challenging that and what the odds are.
MR. DAYAN: I think the odds are zero, Your Honor, but I—
THE COURT: Okay.
MR. DAYAN: — told him that they need to have a conviction. But as a practical matter, Your Honor, it’s really not an issue in this ease.
Later in the colloquy Severino again indicated that the fact that the penalties for a prior felony drug conviction anywhere in a state or federal court would be a mandatory minimum 10 years had been explained to him, and that he understood how the penalties applied to. him and his situation. In response to advice from the court about the importance of telling counsel everything about his past, Severino replied: “I told him everything, yes, sir.”
The AUSA explained that he was having difficulty with the requirement in 21 U.S.C. § 851 to file an information listing all of the prior convictions to be relied on in sentencing. He said that he was not confident that he had all the information that should be in that type of information, “[b]ut I have filed an information today, and I guess the shortness of getting these proceedings on has prevented me from getting this into the hands of the Court and counsel before this proceeding.” The AUSA expressed his belief that the conviction in the information is the same case that counsel talked about, possession of cocaine in Massachusetts in 1992 and 1993, to which Severino’s counsel agreed “that’s the one” and added: “This was set on in a hurry as an accommodation to me so I could go out on vacation, and so we would not object to the fact that we weren’t served in time or that it was filed perhaps a day later since this — the U.S. Attorney’s Office was accommodating me.” Further questioning from the court elicited from defense counsel that he was fully aware of the Massachusetts conviction and he reiterated that it was the same one he had mentioned before. The court also verified from Severino personally that he knew about it and knew that it might trigger a 10-year minimum sentence. All of this took place prior to entry of the guilty plea.
The information filed January 9 to which the AUSA referred alleges:
The prior conviction of the defendant herein, to be relied upon for purposes of sentencing in this case are as follows:
Possession of 1 ounce to 1 kilogram of cocaine, Massachusetts, 1992-1993.
The attached certificate of service represents that a copy of the information was served by deposit in the United States Post Office on Severino’s counsel.
On the same day, the government filed an amended information. It alleges:
The above defendant’s prior conviction to be relied upon for sentencing purposes is as follows:
Possession of 1 ounce to 1 kilogram of cocaine, Rhode Island, 1992-1993.
It, too, was served by mail January 9.
The presentence report, which had been translated into Spanish and given to Sev-erino, and which he reviewed several times with counsel, indicates that the minimum term of imprisonment was ten years, which included the enhanced penalty for Severi-no’s prior felony drug conviction in Rhode Island. The report states that Severino served approximately eight months of his term of imprisonment, then was deported from the United States to the Dominican Republic for being convicted of an aggravated felony. No objections were made to this part of the presentence report, although Severino did object to the recommended two-level enhancement for obstruction of justice and to the presentence [854]*854report’s failure to provide a decrease in the offense level for acceptance of responsibility.
The district court sentenced Severino to imprisonment for ten years, but did not advise him of the right to appeal because of the waiver in the plea agreement. Sev-erino brought no appeal, but one year later, on July 7, 1997, filed a motion under 28 U.S.C. § 2255 to vacate the sentence. Counsel was appointed. The motion challenged the validity of the § 851 information and the lack of advisement of a right to appeal. It was denied, Severino appealed, and a panel of this court remanded for advising Severino of his right to appeal and for resentencing. At resentencing, Severino argued that the information was in error and could not be corrected by the amended information, and that both infor-mations were vague and neither had been served before the plea was taken. The district court rejected these challenges, noting that counsel waived any timing problem with Severino’s concurrence, and that Severino went into the plea agreement expecting a 10-year sentence; Sev-erino admitted he sustained the conviction; there was substantial compliance with § 851; and he was not prejudiced by the information’s failure to specify the proper place of conviction. Accordingly, the court reinstated the original judgment. Severi-no timely appealed.1
II
At the outset, the government urges us to dismiss the appeal because it is barred by Severino’s waiver of appeal. It submits that the limited exceptions to the waiver do not apply because the 10-year sentence was well below the 40-year maximum, his appellate issues are not guideline issues, and the sentence was within both the plea agreement and the expectation of the parties. However, Severino’s appeal is not so constrained; he challenges the court’s authority to enhance his sentence. His appeal waiver, while broad, does not preclude this kind of attack. United States v. Baramdyka, 95 F.3d 840, 843 (9th Cir.1996).
Ill
Severino makes several related arguments leading to the point that the procedural safeguards established by Congress in § 851 must be strictly adhered to or the defendant is not afforded procedural due process. He faults the district court for failing to ask him whether he affirmed or denied the Rhode Island conviction, and to inform him of his right to challenge it. He argues that the court erred in relying on an untimely and inaccurate information of a prior conviction in Massachusetts to enhance the sentence. He notes that neither he nor his counsel actually received a copy of the information, before the plea was taken. Counsel’s failure to object should make no difference, he submits, because these are jurisdictional defects that cannot be cured or waived.2 Finally, Severino maintains that even if the information [855]*855were timely filed and that the amended information corrected only a clerical error, which he contends it did not, still the information was inadequate because it did not provide a number, date of conviction, or sentencing court.
A
We turn first to the government’s compliance with the filing and service requirements of § 851(a).
The sentence of a defendant convicted of a drug offense under § 841(a) may be enhanced for prior convictions for felony drug offenses, 21 U.S.C. § 841(b), but first the government must file an in-formation — and serve a copy on the defendant or counsel — stating in writing the previous convictions upon which it intends to rely. See 21 U.S.C. § 851.3 We expect “strict compliance” with these requirements. United States v. Hamilton, 208 F.3d 1165, 1168 (9th Cir.), cert. denied, 531 U.S. 867, 121 S.Ct. 164, 148 L.Ed.2d 111 (2000). Without it, a court may not enhance a sentence even if a defendant has prior felony drug convictions. As we recently explained in Hamilton, § 851(a) “ensures proper notice so a defendant is able to challenge the information,” and “allows a defendant to make an informed decision about whether or not to plead guilty.” Id.
[856]*856Here, the AUSA represented at the hearing that the information had been filed (i.e., before the plea was taken or entered) and the certificate of service attached to it certifies that the information was served by deposit in the United States Post Office. Regardless, thanks to geography and to defense counsel’s request for a hearing on January 9, the AUSA, the defendant, and his counsel were not in the same place at the same time. Had they been, and had a copy of the information been handed over personally at the hearing, there would be no problem at all. See United States v. Weaver, 905 F.2d 1466, 1481 (11th Cir.1990) (government complied with § 851(a) by serving defendant and his counsel personally before trial). As it happened, however, neither Severino nor his attorney had a copy of the information in hand. Severi-no does not quarrel with service by mail as such,4 but questions whether the government mailed the information prior to the 10:05 a.m. hearing and, in any event, argues that service was defective because the information was not actually received.
Severino’s attorney, however, explicitly waived timely filing and service. Severino does not argue to the contrary. Thus, unless Severino is correct that compliance with § 851(a) is a jurisdictional defect that may not be waived, we need not determine whether the AUSA timely filed the information.
Severino contends, relying on the law of several other circuits, that the procedural requirements of § 851 may not be waived, because compliance is “jurisdictional.” It is true, as Severino argues and as the dissent observes, that the majority of other circuits have referred to the procedural aspects of § 851 as “jurisdictional.”5 But in these matters, it is the quality of the reasoning not the quantity of opinion that counts, and on this basis we cast our lot with the First Circuit. The bottom line is that while the steps prescribed in § 851(a) must be taken before an enhancement is authorized, they are not “jurisdictional” in the sense that the court lacks power to go forward with sentencing (including imposi[857]*857tion of an enhancement for prior convictions). Jurisdiction in this sense is conferred by 18 U.S.C. § 3231.
In Prou v. United States, the First Circuit considered the same jurisdictional argument that Severino presents here. 199 F.3d 37 (1st Cir.1999). That court’s analysis is compelling and bears repetition:
Whether or not the prosecution files a timely section 851(a)(1) information, a federal district court plainly possesses subject-matter jurisdiction over drug cases. See 18 U.S.C. § 3231. This jurisdiction necessarily includes the imposition of criminal penalties. Once subject-matter jurisdiction has properly attached, courts may exceed their authority or otherwise err without loss of jurisdiction. See United States v. Wey, 895 F.2d 429, 431 (7th Cir.1990) (“Courts may err, even offend the Constitution, without losing subject-matter jurisdiction.”); cf. Blackledge v. Perry, 417 U.S. 21, 30, 94 S.Ct. 2098, 40 L.Ed.2d 628 (1974) (indicating that only claims that go “to the very power of the State to bring the defendant into court to answer the charge brought against him” implicate subject-matter jurisdiction). Thus, the only question that legitimately arises from the prosecution’s late filing of a section 851(a)(1) information concerns the court’s authority to impose an enhanced sentence. This is simply not a question of subject-matter jurisdiction.
199 F.3d at 45 (some internal citations and parentheticals omitted). The court went on to note that the term “jurisdiction” is a slippery one; it has a variety of meanings and is often used imprecisely. Id. at 45-46. And in this case, it is used improperly. Put simply, the strictures of § 851 have nothing to do with the subject-matter jurisdiction of the federal courts.6 Rather, the question is whether the requirements of § 851 are subject to waiver. Because jurisdiction is not implicated, the protections contained in § 851 are like the many other statutory provisions that benefit defendants and that may be waived. Id. at 47 (citing United States v. Mezzanatto, 513 U.S. 196, 201, 115 S.Ct. 797, 130 L.Ed.2d 697 (1995)).
There is little more than a house of cards on the other side of the fence. Most of the courts that term § 851 filings “jurisdictional” have failed to delve into the meaning of the term “jurisdiction” or have relied upon authority that is slim, at best. As Judge Easterbrook has observed:
It is easy to find opinions saying that § 851(a) is a jurisdictional rule. Our circuit has at least three. It is considerably harder to find an explanation for this assertion.... Only two courts of appeals have addressed this subject with independent reasoning, as opposed to citations. Prou v. United States, 199 F.3d 37, 42-46 (1st Cir.1999) holds that § 851(a) is not jurisdictional, and United States v. Baucum, 80 F.3d 539, 543-44 (D.C.Cir.1999) resolves a similar issue under 21 U.S.C. § 860(a) against a jurisdictional classification.
United States v. Lawuary, 211 F.3d 372, 378-79 (7th Cir.2000) (Easterbrook, J., concurring) (internal citations omitted).
Two examples illustrate the point. In United States v. Noland, the Fifth Circuit held that § 851 “prohibits an enhanced [858]*858sentence unless the Government seeks it and requires that to obtain enhancement, the Government must file an information prior to trial.” 495 F.2d 529, 533 (5th Cir.1974). The court did not consider whether harmless error analysis applied, but seems implicitly to have held that it does not. “Jurisdiction” was not addressed. Two years later, this decision was recharacterized as follows in United States v. Cevallos: “In Noland, ... the failure to file the information of previous conviction prior to trial deprived the District Court of jurisdiction to impose an enhanced sentence....” 538 F.2d 1122, 1125 n. 4 (5th Cir.1976). The term “jurisdiction” appeared out of nowhere. Nonetheless, Noland and Cevallos became the authority upon which other courts have held that the requirements of § 851 are “jurisdictional.” See, e.g., Harris v. United States, 149 F.3d 1304, 1306-08 (11th Cir.1998); United States v. Belanger, 970 F.2d 416, 418 (7th Cir.1992); Lawuary, 211 F.3d at 378 (noting that the Seventh Circuit’s “cases rest in the end on a misreading of Cevallos ”) (Easterbrook, J., concurring); United States v. Allen, 566 F.2d 1193, 1196 (3d Cir.1977). The Tenth Circuit’s similar holding in United States v. Wright likewise relies upon a Tenth Circuit case that points back to Noland, Eleventh Circuit cases that build off of Noland and Cevallos, and Cevallos itself. 932 F.2d 868, 882 (10th Cir.1991).
Nor is there any reason why a defendant’s rights under § 851 may not be waived. See Mezzanatto, 513 U.S. at 200-02 (noting that waiver of constitutional and statutory rights is presumptively available). It is not enough to dismiss the inquiry into the jurisdictional nature of § 851 and to state that “the Act precludes courts from enhancing sentences unless” § 851 is adhered to. Dissent at 14049. This simply restates the statute’s mandatory language, which begs the question of whether § 851 is subject to waiver. The fact that the language of the statute is mandatory does not answer this question. To the contrary, even rights of a criminal defendant that are created by mandatory statutory language may be waived. See New York v. Hill, 528 U.S. 110, 120 S.Ct. 659, 145 L.Ed.2d 560 (2000) (holding that waiver applies despite statute’s requiring trial schedule within certain time limits and use of mandatory “shall” language); United States v. Piascik, 559 F.2d 545, 549 (9th Cir.1977) (holding that 28 U.S.C. § 753(b), which requires the verbatim transcription of court proceedings, may be waived); see also Prou, 199 F.3d at 47 (“Because section 851(a)(l)’s temporal requirements exist for the defendant’s benefit, it makes perfect sense to give the defendant the power to waive (and the obligation not to forfeit) strict compliance with them.”). Thus, in the absence of a jurisdictional defect, or some other compelling reason that a right may not be waived, see Hill, 528 U.S. at 116-17, 120 S.Ct. 659 (discussing certain rights that are non-waivable), nothing prevents an informed defendant, represented by an informed attorney, from waiving the requirements of § 851.
Here, as the First Circuit noted, jurisdiction is conferred by 18 U.S.C. § 3231. Therefore, the normal rules of waiver, forfeiture, and prejudicial error, apply.7 See Fed.R.Crim.P. 52(a) (“Any er[859]*859ror, defect, irregularity or variance which does not affect substantial’rights shall be disregarded.”)- Applying them here, the AUSA represented that an information had been filed, and what it charged. Sev-erino’s counsel knew that he did not have a copy of it, but did not ask for a continuance or object to proceeding without the information.8 Indeed, he expressly stated that he did not need a copy.
Nor is there any question that Severi-no’s decision about whether to plead guilty was fully informed. He said that he knew that he was subject to a mandatory minimum 10-year sentence on account of a prior felony drug conviction that there was no basis to challenge. He said that he had discussed all of this with counsel. The plea agreement recognized the prospect. And Severino acknowledged his understanding of the consequences to the court.
In sum, to the extent that either the filing or service of the information was not effective, the defect could be, and was, waived. Beyond this, the due process purposes of § 851(a) were served, because Severino was able to make an informed decision about whether or not to plead guilty; he knew exactly what his exposure was.
B
Severino and his counsel also knew exactly what the information alleged, although they had not seen a copy of it, because the AUSA told them so correctly: a prior felony drug conviction in Massachusetts. The problem, of course, is that the place of conviction alleged in the first information turned out to be wrong. A few hours later the government filed an amended information correcting the place. Severino now argues that this was a defect that could not be cured because it was not “clerical.”
In some (indeed, we suspect, in most) cases, this could well be true. Given its statutory ability to ask for the taking of the plea to be postponed, there is little excuse for the government to get its information wrong. However, this case is unlike most cases. In the context of this case, we cannot say that the defect in the first information, or its correction in the amended information, was consequential.
The hearing was held when it was as an accommodation to Severino’s counsel. He and Severino unquestionably knew that Severino had a felony drug conviction, that it was “back east,” and that the AUSA thought it was Massachusetts based on information he had been given but in any event believed it was the same conviction Severino and his counsel had been talking about during the colloquy. They agreed this was so.
There is no possibility that Severino was confused about the prior felony drug conviction that subjected him to the 10-year mandatory minimum sentence. He had been arrested in Massachusetts on driving offenses, but had only been convicted in Rhode Island on a felony drug offense. He stated at the plea hearing that he had told his counsel about all prior convictions and understood that his prior felony drug conviction subjected him to a 10-year man[860]*860datory minimum sentence. There is no evidence of any other drug felony conviction on his record. Counsel said there was no objection to the information being “filed perhaps a day later.” The amended information in fact corrected the place of conviction within the day.
While § 851 clearly prescribes procedural requirements, it says nothing about what the information must aver to conform substantively. See Hamilton, 208 F.3d at 1168-69 (citing other cases to the same effect). Nor does it define what constitutes a “clerical mistake.” However, “[sjection 851 should be interpreted in a manner ‘so as to avoid elevating form over substance.’ ” Id. at 1168, (quoting United States v. King, 127 F.3d 483, 489 (6th Cir.1997)). From the plea negotiations, the plea proceedings, and the first information, Severino had notice that the government intended to seek an enhancement.9 He knew that he had the conviction upon which the government sought to enhance his sentence. As the district court concluded, there was a meeting of the minds. There is no question in the context of this case that the government, Severino and the court were on the same page. For this reason, the amendment could not have been material in Severino’s case. His decision to plead guilty rather than go to trial was fully informed by the mandatory minimum sentence for a prior drug felony conviction that he admitted and agreed was the same one the information was based upon. He never suggested otherwise, sought to withdraw from the plea, or challenged the fact of his Rhode Island conviction. Nor did he ever dispute that the Rhode Island conviction qualified for the enhancement. In these circumstances, we cannot say that the mistake in the first information, cured within the time contemplated by counsel, was material or prejudicial.
C
For the same reasons, we cannot say that the court lacked authority to enhance Severino’s sentence because the amended information failed to provide a case number, date or court. See, e.g., Hamilton, 208 F.3d at 1167 (wrong year); King, 127 F.3d at 489 (wrong date); United States v. Steen, 55 F.3d 1022, 1025-27 (5th Cir.1995) (wrong court number and type of conviction); United States v. Gonzalez-Lerma, 14 F.3d 1479, 1485 (10th Cir.1994) (no number, date or place of conviction, other than state); United States v. Campbell, 980 F.2d 245, 247, 251-52 (4th Cir.1992) (wrong statutory section). In his case (though, we repeat, not necessarily in any other), the amended information provides clear notice of the particular prior conviction upon which the government relied for enhancing the sentence. It was he who first brought up the prior felony drug conviction that would trigger the mandatory minimum sentence. He never objected on the basis that he could not tell which conviction the government was proceeding on for lack of a case number, date or sentencing court. So far as the record discloses, the amended information described the only felony drug offense on which Severino had been convicted. The presentence report based its recommended 10-year mandatory minimum sentence on the Rhode Island conviction, which it described in detail, yet Severino lodged no objection to it.
D
Finally, Severino contends that the district court failed to inquire of him per[861]*861sonally whether he affirms or denies the previous conviction, and to inform him of his right to challenge it. Section 851(b) imposes a duty of inquiry on the district court after an information is filed to determine if the defendant “affirms or denies that he has been previously convicted as alleged in the information,” and a duty of advisement to “inform him that any challenge to a prior conviction which is not made before sentence is imposed may not thereafter be raised to attack the sentence.” 21 U.S.C. § 851(b). Here, the district court failed to do either in so many words. Because we require strict compliance with the procedural aspects of § 851(b), the court plainly erred. Hamilton, 208 F.3d at 1168; United States v. Garrett, 565 F.2d 1065, 1072 (9th Cir.1977) (failure to comply with § 851(b) renders sentence illegal; remanding for resentenc-ing in compliance with its procedures). However, we need not recognize the error, for Severino’s substantial rights were not affected. United States v. Olano, 507 U.S. 725, 734-35, 113 S.Ct. 1770, 123 L.Ed.2d 508 (1993).
Severino admitted the prior drug felony conviction that subjected him to the mandatory minimum 10-year sentence. After full discussion with Severino about his criminal history, counsel told the court that there was no basis for challenging the prior drug felony conviction. Severino never filed a response or denied the allegations of the amended information pursuant to 21 U.S.C. § 851(c)(1). He affirmed the accuracy of the presentence report which listed the Rhode Island conviction as the predicate for sentencing enhancement. And his § 2255 papers concede that there is no basis for challenging the conviction.
It is clear from the circumstances that Severino does not contest the validity of his prior felony drug conviction. Whatever the shortcomings in compliance with § 851(b), Severino was not prejudiced.
AFFIRMED.