dissenting:
The conclusion that a district court has authority to proceed with sentencing despite the government’s admitted failure to comply with the strict procedural requirements of 21 U.S.C. § 851(a) conflicts with the decisions of eight other circuits, the plain statutory language and legislative history. It also cannot be reconciled with our Circuit’s conclusion that the statute imposes mandatory requirements that preclude sentence enhancement if not observed. United States v. Hamilton, 208 F.3d 1165, 1168 (9th Cir.2000), cert. denied, 531 U.S. 867, 121 S.Ct. 164, 148 L.Ed.2d 111 (2000). Thus, I must respectfully dissent.
I
The requirements of 21 U.S.C. § 851(a) are unambiguous and specific:
No person who stands convicted of an offense under this part shall be sentenced to increased punishment by reason of one or more prior convictions, unless before trial, or before entry of a plea of guilty, the United States attorney files an information with the court (and serves a copy of such information on the person or counsel for the person) stating in writing the previous convictions to be relied upon.
The consequences for neglecting to adhere to the statutory procedures are also clear. “The requirement is mandatory, and a district court cannot enhance a defendant’s sentence based on a prior conviction unless the government satisfies the requirement.” United States v. Layne, 192 F.3d 556, 575 (6th Cir.1999) (citing United States v. Williams, 899 F.2d 1526, *8621529 (6th Cir.1990)), cert. denied, 529 U.S. 1029, 120 S.Ct. 1443, 146 L.Ed.2d 330 (2000).
Eight other circuits have concluded that Congress has established an absolute, non-waivable mandate that bars courts from enhancing sentences under § 851(a) unless the government has complied with its requirements. See, e.g., United States v. Lawuary, 211 F.3d 372, 376 n. 6 (7th Cir.2000) (“[T]he requirements of section 851 are jurisdictional in nature.”), cert. denied, 531 U.S. 907, 121 S.Ct. 252, 148 L.Ed.2d 182 (2000); Layne, 192 F.3d at 575; Harris v. United States, 149 F.3d 1304, 1306 (11th Cir.1998) (“The Eleventh Circuit and its predecessor court have unambiguously and repeatedly held that a district court lacks jurisdiction to enhance a sentence unless the government strictly complies with the procedural requirements of § 851(a).”); United States v. Kennedy, 133 F.3d 53, 59 (D.C.Cir.1998) (“Put succinctly, ‘[a] prosecutor’s compliance with § 851(a)(1) is simply a necessary condition to a judge’s imposing an enhanced sentence on the basis of a defendant’s prior convictions.’ ”) (quoting United States v. Vanness, 85 F.3d 661, 663 n. 2 (D.C.Cir.1996)); United States v. Steen, 55 F.3d 1022, 1025 (5th Cir.1995) (“If the prosecution fails to comply with § 851’s procedural requirements, a district court cannot enhance a defendant’s sentence.”); United States v. Gonzalez-Lerma, 14 F.3d 1479, 1485 (10th Cir.1994) (‘“Failure to file the information prior to trial deprives the district court of jurisdiction to impose an enhanced sentence.’ ”) (quoting United States v. Wright, 932 F.2d 868, 882 (10th Cir.1991)); Neary v. United States, 998 F.2d 563, 565 (8th Cir.1993) (“ ‘[T]he statute prohibits an enhanced sentence unless the government first seeks it by properly filing an information prior to trial.’ ”) (quoting United States v. Weaver, 905 F.2d 1466, 1481 (11th Cir.1990)).
Our circuit has not departed from the mainstream. We have categorized the procedures as “mandatory” and bluntly stated that “[i]f the requirement is not satisfied, a court may not enhance a sentence even if a defendant has prior felony drug convictions.” Hamilton, 208 F.3d at 1168. Only the First Circuit has held to the contrary. Prou v. United States, 199 F.3d 37, 45 (1st Cir.1999).
An examination of the plain language of the statute and its legislative history can lead to only one conclusion, and that is the one drawn by almost all of our sister circuits: Congress intended to deny courts the power to impose enhanced sentences absent compliance with the procedures established in § 851.
The procedure for enhancing sentences — and the penalty prescribed for failure to follow it — is in “sharp contrast” with § 851(a)’s predecessor statute. United States v. Olson, 716 F.2d 850, 853 (11th Cir.1983). Prior to 1970, federal law required the United States Attorney, in a drug case, to advise the court after conviction but before sentencing whether the defendant was a recidivist and therefore subject to a mandatory enhanced sentence. 26 U.S.C. § 7237(c)(2) (1964). The prior law was based on a mandatory minimum sentencing scheme under which prosecuto-rial discretion did not play a role. As the Fifth Circuit described it:
The thrust of prior law, which required minimum sentences, was mandatory enhancement. The United States attorney was required to advise the court whether the defendant was a first offender. The court was required to enhance the sentence of a multiple offender, whether or not the prosecutor or the court thought enhancement desirable or necessary.
*863United States v. Noland, 495 F.2d 529, 532 (5th Cir.1974).
Under the prior statute, prosecutors had no choice in deciding whether to seek enhanced sentences based on prior convictions: the statute required the courts to impose sentence enhancement. Thus, notifying the defendant of the prosecutor’s intent would have been superfluous.
Consistent with the theory of mandatory mínimums, the prior statute was also “silent ... as to the consequences of nonfiling of the information prior to imposition of sentence.” United States v. White, 980 F.2d 836, 846 (2d Cir.1992) (Kearse, J., dissenting). Thus, “in this context of con-gressionally ordained mandatory enhancement[J prior cases upheld enhanced sentences despite procedural defects which did not infringe the defendant’s right to deny and litigate his status.” Noland, 495 F.2d at 532. Accordingly, a number of circuits held under the prior law that the government’s failure to timely file an information seeking sentence enhancement was harmless error. See, e.g., King v. United States, 346 F.2d 123, 124 (1st Cir.1965); United States v. Bell, 345 F.2d 354, 357 (7th Cir.1965); United States v. Duhart, 269 F.2d 113, 116 (2d Cir.1959); Knight v. United States, 225 F.2d 55, 57 (9th Cir.1955).
The Comprehensive Drug Abuse Prevention and Control Act of 1970, 21 U.S.C. §§ 801-971, (“the Act”) radically altered existing law and procedure. The “one major goal of the Act was to make more flexible the penalty structure for drug offenses.” Noland, 495 F.2d at 533. “The purpose was to eliminate ‘the difficulties prosecutors and courts have had in the past arising out of minimum mandatory sentences.’ ” Id. (quoting H.R.Rep. No. 91-1444 (1970), reprinted in 1970 U.S.C.C.A.N. 4566, 4576). The theory of the Act was to eliminate mandatory sentences and to invest prosecutors with discretion as to whether to seek enhanced sentences and which prior convictions to invoke. Id. Thus, the statutory scheme was completely everted: rather than requiring courts to impose mandatory minimums regardless of prosecutorial desire, courts were prohibited from enhancing sentences unless the government had timely filed an information stating that it intended to seek an enhanced sentence based on specific prior convictions.
In contrast to the prior statute’s silence about procedural error, the Act specifically addressed the issue. Section 851 provides a remedy for “clerical mistakes,” which may be corrected by filing an amended information prior to the pronouncement of sentence. 21 U.S.C. § 851(a)(1). However, significantly, the Act did not allow a court to excuse or to allow waiver of the failure of the government to timely file an information identifying the crimes. The Act only allows a court to “postpone the trial or the taking of the plea of guilty for a reasonable period” and only then “[u]pon a showing by the United States attorney that facts regarding prior convictions could not with due diligence be obtained prior to trial or before entry of a plea of guilty.” Id.
The new procedural restrictions are firmly rooted in the theory of the Act, which shifted responsibility from judges to impose Congressionally-mandated sentences to prosecutors who were to decide whether to seek enhanced sentences. Under the new statutory scheme, “the district court has no authority to exercise [ ] or pretermit” the exercise of executive discretion. Olson, 716 F.2d at 853. Thus, “[u]n-less and until prosecutorial discretion is invoked and the government files and serves an information as required by § 851, the district court has no power to act with respect to an enhanced sentence.” *864Id. “Harmless error cannot give the district court authority it does not possess.” Id.
Thus, as a matter of statutory construction, it is clear that Congress intended to alter the prior procedures and to impose non-waivable, mandatory requirements. “When Congress acts to amend a statute, we presume it intends its amendment to have real and substantial effect.” Stone v. INS, 514 U.S. 386, 397, 115 S.Ct. 1537, 131 L.Ed.2d 465 (1995). We also presume that when Congress amends a statute, it is knowledgeable about judicial decisions interpreting the prior legislation. United States v. Hunter, 101 F.3d 82, 85 (9th Cir.1996). Further, “[a] particular statutory provision must be read in context with a view to its place in the statutory scheme.” Gorbach v. Reno, 219 F.3d 1087, 1093 (9th Cir.2000). Finally, and perhaps most importantly, we generally presume that “Congress ‘says in a statute what it means and means in a statute what it says there.’” Hartford Underwriters Ins. Co. v. Union Planters Bank, N.A., 530 U.S. 1, 6, 120 S.Ct. 1942, 147 L.Ed.2d 1 (2000) (quoting Conn. Nat’l Bank v. Germain, 503 U.S. 249, 254, 112 S.Ct. 1146, 117 L.Ed.2d 391 (1992)). Given the plain language of § 851(a), its structure (namely, the specific remedies provided for procedural violations), the substantive alteration from prior law, and the import of judicial construction, there is no doubt that Congress meant what it said in providing that no person could be subjected to enhanced penalties based on prior convictions unless the government timely filed an information identifying the convictions upon which it intended to rely and served it on the defendant or his attorney.
In this case, it is clear that the United States failed to serve the amended information prior to Severino’s change of plea hearing. Indeed, the district court specifically acknowledged this fact in its order denying Severino’s § 2255 motion when it observed at the plea hearing that: “[The government] was not able to have [Severi-no’s lawyer] or Severino served with copies of the information prior to the commencement of the Rule 11 plea hearing.” Further, the Assistant United States Attorney admitted that, “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 district court was unaware of any filing at the hearing. The information was also incorrect and, as stated, could not sustain a sentence enhancement. Thus, because the procedural prerequisites of § 851 were not observed, the district court was without power to impose an enhanced sentenced in this case, regardless of whether Severino waived his § 851 rights or not.1
II
The majority’s reliance on Prou is, I respectfully suggest, misplaced. First, the Prou court proceeded from the false prem*865ise that if courts possess subject matter jurisdiction, they also possess the power to sentence outside their statutory authority. Second, in the context of the Act, application of the Prou court’s rule would violate the separation of powers. Lastly, Prou’s rationale is inapplicable to this case because Prou involved issues of waiver in the context of a collateral habeas challenge, rather than on direct appeal.
The Prou court’s primary quarrel is with the categorization of § 851’s requirements as “jurisdictional” by some circuits. The Prou court observed that “a federal district court plainly possesses subject-matter jurisdiction over drug cases.” 199 F.3d at 45 (citing 18 U.S.C. § 3231). Therefore, the panel reasoned, because non-jurisdictional defects are subject to waiver, the requirements of § 851 may be waived. Id. at 47.
This syllogism fails because it proceeds from a false premise, namely, that if subject matter jurisdiction is not implicated, then courts have the power to abrogate specific statutory restrictions on their sentencing authority. This is untrue. Absent unconstitutional statutory restrictions, courts cannot exceed their statutory grant of authority in sentencing defendants. Melendez v. United States, 518 U.S. 120, 130, 116 S.Ct. 2057, 135 L.Ed.2d 427 (1996) (holding that a district court “lack[s] the authority” to sentence a defendant below the statutory minimum absent a motion from the government); United States v. Barragan-Mendoza, 174 F.3d 1024, 1028-30 (9th Cir.1999) (holding that, pursuant to Federal Rule of Criminal Procedure 35(c), the district court lacks jurisdiction to amend a sentence more than seven days after its imposition even though the defendant agreed at the amendment hearing that the court did have authority); United States v. Doe, 53 F.3d 1081, 1083-84 (9th Cir.1995) (“We find no statutory authority for sentencing adjudicated juvenile delinquents to supervised release.”).
The fact that the Act confines the court’s authority makes it different from other mandated statutory and constitutional procedures. The latter may, of course, be waived. But one cannot grant a court power by stipulation. A sentence imposed in excess of the court’s statutory authority is illegal even if the defendant has agreed to the punishment. United States v. Snider, 957 F.2d 703, 706-07 (9th Cir.1992) (per curiam) (reversing the imposition of restitution, raised for the first time on appeal, noting “Federal courts have no inherent power to order restitution.... Restitution, as a criminal punishment, is subject to the general rule that plea agreements do not provide authority for a sentencing court to impose punishment in excess of the maximum provided by statute.”); Launius v. United States, 575 F.2d 770, 772 (9th Cir.1978) (“[Ajlthough prosecutors are given wide latitude in plea bargaining, they cannot legitimatize, through plea bargaining, the imposition of penalties in excess of the statutory maximum for the offense charged.”).
Thus, the holding by the vast majority of other circuits that courts lack authority to enhance a sentence absent compliance with § 851 was not a product of judicial shamanism. It followed the statutory command. Congress plainly provided that, unless the government timely files an information identifying the relevant convictions, “[n]o person who stands convicted of an offense under this part shall be sentenced to increased punishment by reason of one or more prior convictions.” 21 U.S.C. § 851(a)(1).
To be sure, district courts are vested with original jurisdiction “of all offenses against the laws of the United States.” 18 U.S.C. § 3231. But this jurisdictional grant does not empower a court to impose *866a sentence contrary to law. Not only do courts lack power to impose sentences in excess of statutory authority, Doe, 53 F.3d at 1083-84, but the imposition of such a sentence constitutes plain error. United States v. Guzman-Bruno, 27 F.3d 420, 423 (9th Cir.1994). Thus, whether one construes § 851 as a jurisdictional statute or not is largely beside the point. The Act precludes courts from enhancing sentences unless specified statutory procedures are observed. If the statute is violated, then that portion of the sentence imposed in excess of statutory authority is void. United States v. Pridgeon, 153 U.S. 48, 62, 14 S.Ct. 746, 38 L.Ed. 631 (1894).
A
Application of the Prou rationale in the specific context of the Act would also violate the separation of powers in two respects: (1) the power of Congress to define criminal sentences and (2) the power of the executive branch to control prosecutions.
First, it is “indisputable” that “the authority to define and fix the punishment for crime is legislative.” Ex parte United States, 242 U.S. 27, 42, 37 S.Ct. 72, 61 L.Ed. 129 (1916). There are no federal common law crimes. Liparota v. United States, 471 U.S. 419, 424, 105 S.Ct. 2084, 85 L.Ed.2d 434 (1985); see also United States v. Coolidge, 14 U.S. (1 Wheat.) 415, 416, 4 L.Ed. 124 (1816); United States v. Hudson and Goodwin, 11 U.S. (7 Cranch) 32, 34, 3 L.Ed. 259 (1812). It is by legislative action that crimes and criminal procedure are defined; therefore, a court has no power to impose a sentence in excess of statutory authority. Doe, 53 F.3d at 1083-84. As this court, sitting en banc, has noted, “[t]he Supreme Court has stated unequivocally that ‘Congress has the power to define criminal punishments without giving the courts any sentencing discretion.’” United States v. Kaluna, 192 F.3d 1188, 1199 (9th Cir.1999) (en banc) (quoting Chapman v. United States, 500 U.S. 453, 467, 111 S.Ct. 1919, 114 L.Ed.2d 524 (1991)). In Kaluna, we noted that the federal three strikes statute, 18 U.S.C. 3559, used words such as “mandatory” and “shall,” and we concluded that Congress had stripped the court of sentencing discretion, thereby mandating imposition of a life sentence for the defendant — despite the high risk of an erroneous classification of one crime as a “strike.” Id.
So it is with § 851. In passing the Act, Congress altered the statutory scheme and expressly stripped courts of the authority to impose an enhanced sentence in the absence of a properly and timely-filed information. Congress grants judicial criminal sentencing power; parties do not.
Second, by granting the executive branch the discretion to decide whether a sentence enhancement should be sought, the Act concomitantly removed that authority from the judiciary. Just as courts cannot commit an unindicted person to prison, courts cannot enhance a sentence under § 851 until the government elects formally to proceed with a sentence enhancement. Olson, 716 F.2d at 853. Thus, in this context, to allow courts to impose a sentence without the valid exercise of executive discretion would interfere with prosecutorial discretion. As we have previously observed, “separation of powers concerns prohibit us from reviewing a prosecutor’s charging decisions absent a prima facie showing that it rested on an impermissible basis, such as gender, race or denial of a constitutional right.” United States v. Palmer, 3 F.3d 300, 305 (9th Cir.1993). Indeed, “we have no jurisdiction to review prosecutors’ charging decisions, absent proof of discrimination based on suspect characteristics such as race, religion, gender or personal beliefs.” *867United States v. Oakes, 11 F.3d 897, 899 (9th Cir.1993). As we recently stated en bane, “Courts generally have no place interfering with a prosecutor’s discretion regarding whom to prosecute, what charges to file, and whether to engage in plea negotiations.” United States v. Banuelos-Rodriguez, 215 F.3d 969, 976 (9th Cir.2000). Under the Act, until the executive branch validly exercises its option to seek a sentence enhancement, the courts are powerless to impose one. Thus, the Prou rationale implicates the separation of judicial and executive powers, as well as the separation of judicial and legislative powers.
B
Finally, the posture of this case also differs significantly from that of Prou. Prou was a pro se collateral challenge; this is a direct appeal. Prou’s attorney had neglected to raise the issue on direct appeal. 199 F.3d at 41-42. Thus, the issue of whether § 851(a) implicated subject matter jurisdiction was important because, if it did not, then Prou would have to show cause and prejudice for his failure to raise the issue on direct appeal. Id. at 47. In analyzing whether Prou could avoid procedural default, the Prou court noted:
In this case, the relevant error is the failure to object to an impuissant filing, resulting in the imposition of a sentence not authorized by law.
Id.
Based on that consideration, the court found the requisite “cause” because it was constitutionally ineffective assistance of counsel not to challenge a sentence enhancement imposed contrary to law. Id. at 48. The court also found prejudice because without the government’s proper filing under § 851(a), “the district court would not have had recourse to a ten-year mandatory minimum sentence.” Id. at 49. Thus, the court reasoned, “[t]he subsequent imposition of such a sentence is prejudice, pure and simple.” Id. The court then remanded for resentencing without the enhancement, noting that “we decline to grant the government the windfall of an unlawful sentence enhancement.” Id. at 49 n. 7, 50. The ultimate result in Prou was not to enforce the defendant’s waiver; it was to set aside the enhanced sentence.
Thus, the context of the “jurisdictional” discussion in Prou was far different. The Prou court was concerned about whether to apply the usual rules of procedural default on habeas review; it was not deciding on direct appeal whether a court could impose a sentence outside statutory authority. That claim, as the Prou court noted in its cause and prejudice discussion, was “a clear winner.” Id. at 48.
For all of these reasons, it is inappropriate to apply, much less extend, Prou in the present context. The majority erred in doing so.
Ill
In addition to the pure question of statutory interpretation, there are constitutional considerations in adhering to the procedures designated in § 851. “Due process requires that a defendant receive reasonable notice and an opportunity to be heard regarding the possibility of an enhanced sentence for recidivism.” United States v. Belanger, 970 F.2d 416, 418 (7th Cir.1992) (citing Oyler v. Boles, 368 U.S. 448, 452, 82 S.Ct. 501, 7 L.Ed.2d 446 (1962)). “The purpose of notice under the Due Process , Clause is to apprise the affected individual of, and permit adequate preparation for, an impending ‘hearing.’” Memphis Light, Gas and Water Div. v. Craft, 436 U.S. 1, 14, 98 S.Ct. 1554, 56 L.Ed.2d 30 (1978). To comport with due process, “[t]he notice must be of such nature as reasonably to *868convey the required information.” Mullene v. Cent. Hanover Bank & Trust Co., 339 U.S. 306, 314, 70 S.Ct. 652, 94 L.Ed. 865 (1950).
“Section 851 was enacted to fulfill this due process requirement.” Belanger, 970 F.2d at 418. The statute “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.” Hamilton, 208 F.3d at 1168. It also permits a defendant “to plan his trial strategy with full knowledge of the consequences of á potential guilty verdict.” United States v. Johnson, 944 F.2d 396, 407 (8th Cir.1991).
When a defendant decides to enter a guilty plea, the filed information becomes especially important because the defendant needs to make an informed choice. The fact that the government may be seeking the imposition of a mandatory sentence through a § 851 enhancement — and the basis for the enhancement — is critical information. Providing the defendant with a copy of the information helps assure the court that the defendant is entering a plea intelligently, voluntarily and with full knowledge of the consequences.
It is not uncommon for everyone but the defendant to be on the same page at a change of plea or sentencing hearing. In such cases, the proceedings are usually interrupted to make certain that the defendant personally understands the rights he is relinquishing and the sentence to which he may be exposed. Indeed, postponement of the hearing is the only remedy allowed by the Act when the government has failed to file a timely information. 21 U.S.C. § 851(a)(1). Thus, in addition to conforming to the statute, compliance with § 851 assures us that minimum due process requirements have been fulfilled.
IV
Having said all this, I cannot conclude without observing that, in my opinion, both the district court and the government proceeded in absolute good faith in this unusual case. My differences are founded on the limitations Congress placed on the courts in enacting § 851. Although many rights may be waived, the parties cannot agree to grant a court extra-statutory sentencing power. Thus, even if Severino had effectively waived his § 851 rights, the district court lacked the power to impose the mandatory minimum sentence because the statutory predicates were not satisfied.
For these reasons, I respectfully dissent.
. Because my disagreement is one of statutory interpretation, I have assumed, arguendo, that Severino made an effective waiver of his right to contest the information under § 851. In fairness to Severino, the record is far less clear. Severino never personally waived his rights under § 851. The waiver claim is based solely on the statement made by Severi-no's attorney at the change of plea hearing that "[t]his was set on in a hurry as an accommodation to me so I could go 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 — the U.S. Attorney’s Office was accommodating me.” There was no representation that defense counsel had consulted with Severino prior to interjecting the spontaneous objection waiver. It is also evident that Severino and his attorney had some difficulty in communicating because Severino did not speak English and only had a limited education.