OPINION
PAGE, Justice.In an order issued last December, we determined that under Blakely v. Washington, 542 U.S. 296, 124 S.Ct. 2531, 159 L.Ed.2d 403 (2004), the district court’s imposition of an upward durational departure from the presumptive sentence prescribed by the Minnesota Sentencing Guidelines violated appellant Robert Shattuck’s Sixth Amendment right to trial by jury. State v. Shattuck, 689 N.W.2d 785, 786 (Minn.2004). We indicated a full opinion would follow, and we directed the parties to file supplemental briefs on the issue of remedy-
*134The issues presented by this appeal arise out of the sexual assault of 17-year-old R.E. At about 10:30 p.m. on January 30, 2001, R.E. was walking home after getting off a bus in south Minneapolis when a man pushing a bicycle approached her from behind and asked the time. As R.E. reached for her watch, the man displayed a knife, threatened her, and forced her to walk down an alley. When they stopped, the man took $25 from R.E.’s pocket and told her to pull down her pants. From behind, he penetrated her vaginally with his fingers and penis, causing her pain. When R.E. asked him to stop, the man threatened her again. After the man finished, he cleaned his hands in the snow and then punched R.E. in the face, breaking her jaw. The man told R.E. that if she told anyone about the assault he would kill her, and rode away on his bicycle.
The police investigation quickly focused on Shattuck, who worked at a nearby restaurant and had gotten off work shortly before the assault. After Shattuck’s picture was shown on a televised report about the assault, he went to Georgia, where he was arrested on an unrelated charge. At trial, the state introduced substantial circumstantial evidence as well as DNA evidence linking Shattuck to the assault. At the jury instruction conference, Shattuck argued that under Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000), any aggravating factor that could expose him to an enhanced sentence under Minnesota’s repeat sex offender statute had to be decided by the jury, not the district court. The court denied Shattuck’s request to so instruct the jury. The jury found Shattuck guilty of two counts of kidnapping, two counts of first-degree criminal sexual conduct, and one count of first-degree aggravated robbery.
At the time of the offense, first-degree criminal sexual conduct and kidnapping with great bodily harm were both severity level eight offenses under the Minnesota Sentencing Guidelines. Minn. Sent. Guidelines IV, V (2000). Shattuck’s criminal history score was nine, which included a custody status point, making his presumptive sentence 161 (156-166) months for these offenses.1 Minn. Sent. Guidelines II.B.2, IV (2000). The repeat sex offender statute provides that for certain forms of first- and second-degree criminal sexual conduct, the district court “shall commit” the defendant for not less than 30 years if it finds that (1) an aggravating factor exists which provides grounds for an upward departure under the Sentencing Guidelines, and (2) the defendant has a previous conviction for criminal sexual conduct in the first, second or third degrees. Minn.Stat. § 609.109, subd. 4(a) (2004).2
The district court sentenced Shattuck to the presumptive 161-month prison term for kidnapping, and to an enhanced 360-month (30-year) term for first-degree criminal sexual conduct pursuant to section 609.109, subdivision 4, and ordered the sentences to be served concurrently. The *135court found four aggravating factors to justify the enhanced sentence: (1) the victim was particularly vulnerable; (2) the victim was treated with particular cruelty; (3) -the victim suffered great emotional harm; and (4) the assault was planned.
The court of appeals affirmed Shattuck’s conviction and sentence. State v. Shattuck, No. C6-03-362, 2004 WL 772220 (Minn.App. Apr.13, 2004). The court held that the district court “acted within its discretion in finding that aggravating factors provided a sufficient basis for sentencing Shattuck under the mandatory-minimum-sentencing statute, and that decision did not violate the holding of Apprendi.” Id. at *6. While Shattuck’s petition for review was pending in this court, the United States Supreme Court issued its decision in Blakely. In accordance with the rule announced in that case, we reverse the court of appeals and remand to the district court.
I.
The first issue before us is whether the imposition of an enhanced sentence under Minn.Stat. § 609.109, subd. 4, which mandates a 30-year minimum sentence when the district court determines at sentencing that “the crime involved an aggravating factor that would provide grounds for an upward departure under the Sentencing Guidelines,” violated Shattuck’s Sixth Amendment right to trial by jury. In our earlier order in this case, we answered this question in the affirmative, and stated that “because imposition of the presumptive sentence is mandatory absent judicial findings under the legislatively-created Guidelines regime, the presumptive sentence is the maximum penalty authorized solely by the jury’s verdict for purposes of Apprendi v. New Jersey, 530 U.S. 466, 120 S.Ct. 2348, 147 L.Ed.2d 435 (2000).” State v. Shattuck, 689 N.W.2d at 786.
Issues of constitutional interpretation are issues of law that we review de novo. Star Tribune Co. v. Univ. of Minn. Bd. of Regents, 683 N.W.2d 274, 283 (Minn.2004). Minnesota statutes are presumed constitutional, and the party challenging a statute on constitutional grounds must demonstrate, beyond a reasonable doubt, that the statute violates a provision of the constitution. State v. Grossman, 636 N.W.2d 545, 548 (Minn.2001).
We begin the analysis in this case by noting that the rule that has evolved in the Apprend/i line of cases is based on the constitutional right to jury trial and the requirement of proof beyond a reasonable doubt. Apprendi v. New Jersey, 530 U.S. at 477, 120 S.Ct. 2348; Blakely v. Washington, 124 S.Ct. at 2536; United States v. Booker, 543 U.S.-, 125 S.Ct. 738, 748, 160 L.Ed.2d 621 (2005). The Supreme Court explained in Booker that as sentencing enhancements have increased in recent years the jury’s findings as to the underlying crime have become less significant. Id. at 751. “The new sentencing practice forced the Court to address the question how the right of jury trial could be preserved, in a meaningful way guaranteeing that the jury would still stand between the individual and the power of the government under the new sentencing regime. * * * [The] answer [is] not motivated by Sixth Amendment formalism, but by the need to preserve Sixth Amendment substance.” Id. at 752. The constitutional rule that has evolved is:
Any fact (other than a prior conviction) which is necessary to support a sentence exceeding the maximum authorized by the facts established by a plea of guilty or a jury verdict must be admitted by the defendant or proved to a jury beyond a reasonable doubt.
Id. at 756.
In Apprendi, the defendant pleaded guilty to possession of a firearm for an *136unlawful purpose, stemming from his firing several gunshots into the home of an African-American family that had recently moved into an all-white neighborhood. 530 U.S. at 469, 120 S.Ct. 2348. Under New Jersey law, the offense earned a penalty range of 5 to 10 years. Id. at 470, 120 S.Ct. 2348. A separate hate-crime statute provided for an enhanced sentencing range of 10 to 20 years if the trial judge found, by a preponderance of the evidence, that the defendant committed the crime with a purpose to intimidate an individual or group of individuals because of, inter alia, race. Id. at 468-69,120 S.Ct. 2348. Following an evidentiary hearing, the trial judge found that Apprendi’s actions were made with a purpose to intimidate, and imposed an enhanced 12-year term. Id. at 471,120 S.Ct. 2348.
The Supreme Court reversed, holding that the New Jersey statutory scheme allowing the judge to impose an enhanced sentence, based on a judicial finding using a preponderance standard, violated constitutional due process and jury-trial guarantees. Id. at 476-77, 491-92, 120 S.Ct. 2348; see State v. Grossman, 636 N.W.2d at 548. The Court announced the following rule: “Other than the fact of a prior conviction, any fact that increases the penalty for a crime beyond the statutory maximum must be submitted to a jury, and proved beyond a reasonable doubt.” Apprendi 530 U.S. at 490,120 S.Ct. 2348. In reaching this conclusion, the Court described the distinction between elements of the crime and sentencing factors as “constitutionally novel and elusive,” and made clear that “the relevant inquiry is not one of form but of effect — does the required finding expose the defendant to a greater punishment than that authorized by the jury’s verdict?” Id. at 494, 120 S.Ct. 2348 (footnote omitted); Grossman, 636 N.W.2d at 550-51 (footnote omitted).
Following Apprendi this court applied its rule in a number of cases. In Gross-man, we held that the patterned sex offender statute, which allowed the judge to increase by 10 years the maximum prison sentence prescribed by the first-degree criminal sexual conduct statute, based on the judge’s factual findings using a pre-ponderanee-of-evidenee standard, violated due process. 636 N.W.2d at 551. See also O’Meara v. State, 679 N.W.2d 334, 340-41 (Minn.2004) (holding sentences imposed pursuant to patterned sex offender statute that enhanced by 15 years maximum sentence prescribed by second-degree criminal sexual conduct statute to be unconstitutional). We have also held that imposition of a mandatory conditional release term for sex offenders is permissible under Apprendi, but that an enhanced conditional release term under the patterned sex offender statute, on top of an already-enhanced prison sentence under the same statute, violated due process because it exceeded the maximum sentence prescribed for the offense of conviction and was imposed based on judicial findings using a preponderance standard. State v. Jones, 659 N.W.2d 748, 752-53 (Minn.2003). In State v. Smith, 669 N.W.2d 19, 33 (Minn.2003), we addressed the constitutionality of enhancing the minimum prison term for first-degree murder, from life in prison with the possibility of release after 30 years to life imprisonment without the possibility of release when the defendant has a prior conviction for a “heinous” crime. We concluded that Apprendi principles were not implicated because only the minimum term of imprisonment is affected by the finding of a heinous crime, and therefore the determination of a prior heinous crime conviction may be found by the district court. Id. (relying on Harris v. United States, 536 U.S. 545, 567, 122 S.Ct. 2406, 153 L.Ed.2d 524 (2002) (holding that Apprendi did not *137preclude judge from making factual determination affecting minimum sentence)).3
The Supreme Court subsequently extended Apprendi to sentencing guidelines regimes. In Blakely, the defendant pleaded guilty to kidnapping his estranged wife, an offense which, under the applicable criminal statutes, carried a maximum penalty of 10 years’ imprisonment. 124 S.Ct. at 2535. Washington’s sentencing guidelines called for a “standard range” sentence of 49 to 53 months for the offense. Id. The guidelines also permitted a judge to impose an “exceptional sentence” above the standard range if the judge found “substantial and compelling” reasons to do so. Id. Following a hearing, the judge imposed a 90-month exceptional sentence, finding that Blakely had acted with “deliberate cruelty.” Id. The Court reversed, holding:
[T]he “statutory maximum” for Appren-di purposes is the maximum sentence a judge may impose solely on the basis of the facts reflected in the jury verdict or admitted by the defendant. ⅜ * * In other words, the relevant “statutory maximum” is not the maximum sentence a judge may impose after finding additional facts, but the maximum he may impose loithout any additional findings.
Id. at 2537. Thus, the enhanced sentence imposed in Blakely was unconstitutional even though it did not exceed the 10-year maximum prescribed by the criminal statutes.
In Booker, the Supreme Court held that the Sixth Amendment as construed in Blakely applies to the Federal Sentencing Guidelines. 125 S.Ct. at 746. In both of the consolidated cases before the Court, a jury found the defendant guilty of a drug distribution offense, and the district court made factual findings at sentencing, by a preponderance of the evidence, that subjected the defendant to a sentence many years beyond the guidelines sentence authorized by the jury verdict alone. Id. at 746-47. The Supreme Court concluded that “there is no distinction of constitutional significance” between the Federal Sentencing Guidelines and the Washington procedures at issue in Blakely because under both systems, the relevant sentencing rules are mandatory and impose binding requirements on all sentencing judges. Id. at 749-50. The Court added that if the guidelines were merely advisory, “their use would not implicate the Sixth Amendment. We have never doubted the authority of a judge to exercise broad discretion in imposing a sentence within a statutory range.” Id. at 750 (citations omitted). See also Blakely, 124 S.Ct. at 2540 (stating that indeterminate sentencing does not infringe on province of jury). By a different majority, the Court went on to excise mandatory provisions of the federal Sentencing Act and make the federal guidelines advisory. Id. at 764-65.
We now turn to the constitutionality of Shattuck’s sentence enhancement imposed pursuant to the repeat sex offender statute. As stated earlier, this statute mandates that the district court impose a 30-year minimum sentence for certain repeat sex offenders if it finds, at the time of sentencing, that an aggravating factor exists which provides grounds for an upward departure under the Sentencing Guidelines. Minn.Stat. § 609.109, subd. 4(a). We note at the outset that the 30-year minimum sentence prescribed by this statute is also the maximum sentence for the offense of first-degree criminal sexual eon-*138duct, the crime of conviction for which Shattuck’s sentencing enhancement was imposed. Minn.Stat. § 609.342, subd. 2(a) (2004). We also note that because section 609.109, subdivision 4, expressly incorporates the procedures of the Sentencing Guidelines for upward durational departures, the constitutional validity of the statute necessarily implicates the constitutional validity of upward durational departures under the Sentencing Guidelines.4
The state argues that the Sentencing Guidelines as written are advisory to the district court and therefore do not implicate Sixth Amendment concerns. In support, the state points to statutory language which specifies that the guidelines are advisory and that sentencing pursuant to the guidelines is not a right that accrues to the defendant. See Minn.Stat. § 244.09, subd. 5 (2004). Citing remarks made by the first director of the Sentencing Guidelines Commission in 1979, the state contends that the guidelines have been advisory since their inception. See Remarks of Dale G. Parent prepared for delivery at National Conference of State Legislators, Development of Statewide Sentencing Guidelines in Minnesota (Minn. Sent. Guidelines Comm’n July 1979). The state further argues that the Minnesota Sentencing Guidelines are less mandatory than the “reformed” Federal Sentencing Guidelines following the Booker decision, and that boundaries on the sentencing discretion of Minnesota judges are practically nonexistent. We disagree with the state’s position.
If the Minnesota Sentencing Guidelines were merely advisory — if they constituted no more than a rough map to steer the district court in exercising sentencing discretion — they would suffer from no constitutional infirmity. Booker, 125 S.Ct. at 750. Were this the case, the relevant statutory maximum for Blakely purposes in this case would be the maximum sentence set out in the criminal sexual conduct statute, not the presumptive sentence prescribed by the guidelines. This, however, is not the case before us.
The Minnesota Sentencing Guidelines were promulgated by the Sentencing Guidelines Commission (“Commission”), which was created by the legislature in 1978. Act of April 5, 1978, ch. 723, art. I, § 9, subd. 5, 1978 Minn. Laws 761, 766 (codified as Minn.Stat. § 244.09, subd. 5 (2004)). The legislature provided that the guidelines “shall be advisory to the district court and shall establish” both (1) the circumstances under which imprisonment of an offender is proper, and (2) “[a] presumptive, fixed sentence for offenders for whom imprisonment is proper, based on each appropriate combination of reasonable offense and offender characteristics.” Id. The act required the Sentencing Guidelines to be submitted to the legislature and provided that they “shall be effective May 1,1980, unless the legislature provides otherwise.” Id., § 9, subd. 12, 1978 Minn. Laws at 767 (codified as Minn.Stat. § 244.09, subd. 12 (2004)).
The legislature also set out certain procedures to be followed for deviations from the Sentencing Guidelines. Id., § 10, 1978 Minn. Laws at 767-68 (codified as Minn. Stat. § 244.10 (2004)). It specifically provided that when the district court imposes or stays a sentence that deviates from the guidelines, the court “shall make written *139findings of fact as to the reasons for departure * * Id., § 10, subd. 2,1978 Minn. Laws at 768 (emphasis added). The legislature further provided for broad appellate review of sentences “to determine whether the sentence is inconsistent with statutory requirements, unreasonable, excessive, unjustifiably disparate, or not warranted by the findings of fact issued by the district court.” Id., § 11, 1978 Minn. Laws at 768 (codified as Minn.Stat. § 244.11 (2004)).
In 1997, the legislature amended Minn. Stat. § 244.09, subd. 5, by adding language that, “[ajlthough the sentencing guidelines are advisory to the district court, the court shall follow the procedures of the guidelines when it pronounces sentence * * Act of May 6, 1997, ch. 96, § 1, 1997 Minn. Laws 694, 695 (emphasis added). The 1997 amendment also provided that sentencing pursuant to the guidelines “is not a right that accrues to a person convicted of a felony; it is a procedure based on state public policy to maintain uniformity, proportionality, rationality, and predictability in sentencing.” Id.5
The Sentencing Guidelines promulgated by the Commission employ a grid to determine the presumptive sentence for felonies. Minn. Sent. Guidelines II.C., IV (Sentencing Guidelines Grid). The vertical axis of the grid represents the severity of the offense and is arrayed into 11 severity levels. Minn. Sent. Guidelines II.A, IV. The horizontal axis represents the defendant’s criminal history score, comprised of prior convictions, applicable juvenile record, and custody status at the time of the current offense. Minn. Sent. Guidelines II.B, IV, V (Offense Severity Reference Table). A bold line on the grid demarcates those offenses for which the presumptive sentence is executed from those for which the presumptive sentence is stayed. Minn. Sent. Guidelines II.C, IV. The grid provides for a presumptive fixed sentence and, for those sentences which are presumptively executed, a presumptive sentencing range.6 Minn. Sent. Guidelines II.C, IV. Any prison sentence outside the presumptive range constitutes a departure and requires the judge to provide written reasons. Minn. Sent. Guidelines II.C.
Minnesota Sentencing Guidelines II.D states that the sentencing judge “shall utilize the presumptive sentence” unless the individual case involves “substantial and compelling circumstances” (emphasis added). When such circumstances are present, the judge “may depart from the presumptive sentence and stay or impose any sentence authorized by law.” Id. When *140departing, the judge should “pronounce a sentence which is proportional to the severity of the offense of conviction and the extent of the offender’s prior criminal history, and should take into substantial consideration the statement of purpose and principles” of the guidelines. Id. A judge who departs from the presumptive sentence must provide written reasons which both specify the substantial and compelling nature of the circumstances and demonstrate why the sentence is more appropriate, reasonable or equitable than the presumptive sentence. Id. The guidelines then list factors that should not be used for departure and nonexclusive aggravating and mitigating factors that may be used as reasons for departure. Minn. Sent. Guidelines II.D.l and 2.
In this court’s first decision construing the Sentencing Guidelines, we stated: “Underlying the Guidelines is the notion that the purposes of the law will not be served if judges fail to follow the Guidelines in the ‘general’ case.” State v. Garcia, 302 N.W.2d 643, 647 (Minn.1981). That same year we indicated that it would be a “rare case” that would warrant reversal of the refusal to depart from a presumptive sentence. State v. Kindem, 313 N.W.2d 6, 7 (Minn.1981).
We review the district court’s decision to depart from the guidelines’ presumptive sentence for an abuse of discretion. Garcia, 302 N.W.2d at 647. But we have emphasized that the district court has discretion to depart “only if aggravating or mitigating circumstances are present;” if such circumstances are not present, “the trial court has no discretion to depart.” State v. Best, 449 N.W.2d 426, 427 (Minn.1989). We also require the district court to include a statement of the reasons for departure on the record at the time of sentencing in order for a departure to be allowed. State v. Geller, 665 N.W.2d 514, 517 (Minn.2003).
Additionally, we have placed limitations on the length of durational sentencing departures. As a general rule, the maximum upward durational departure that can be justified by aggravating circumstances is double the presumptive sentence. State v. Evans, 311 N.W.2d 481, 483 (Minn.1981). Only in cases of “severe aggravating circumstances” may the district court impose a greater-than-double departure from the presumptive sentence; in such cases the only absolute limit on duration is the maximum provided in the statute defining the offense. State v. Mortland, 399 N.W.2d 92, 94 & n. 1 (Minn.1987). Such cases, we have stated, are “extremely rare.” State v. Spain, 590 N.W.2d 85, 89 (Minn.1999).
A basic tenet of Sentencing Guidelines jurisprudence is that the district court may not base an upward dura-tional departure on factors that the legislature has already taken into account in determining the degree or seriousness of the offense. See, e.g., Taylor v. State, 670 N.W.2d 584, 589 (Minn.2003); State v. McIntosh, 641 N.W.2d 3, 11 (Minn.2002). Additionally, while it is generally proper for the court to consider the conduct underlying the offense of which the defendant is convicted, reliance on other offenses that are not part of that offense and of which the defendant was not convicted is not a permissible basis for a durational departure. Taylor, 670 N.W.2d at 588.
This survey of pertinent law makes clear that the district court has limited sentencing discretion under the Minnesota Sentencing Guidelines. In particular, we conclude that in imposing sentence for a felony, the district court is required to impose the presumptive sentence set out in the Sentencing Guidelines *141Grid absent additional findings. Section II.D of the guidelines expressly provides that the court “shall utilize the presumptive sentence” unless substantial and compelling circumstances are present. While the statute authorizing promulgation of the Sentencing Guidelines states that they are advisory to the district court, it expressly provides that the district court “shall follow the procedures of the guidelines” in pronouncing sentence. MinmStat. § 244.09, subd. 5. Under the canons of statutory construction, “shall” is mandatory. Minn.Stat. § 645.44, subd. 16 (2004); State v. Humes, 581 N.W.2d 317, 319 (Minn.1998). Utilization of the presumptive sentence under Minn. Sent. Guidelines II.D is one of the “procedures of the guidelines” the statute requires the district court to follow. Similarly, in our jurisprudence during the quarter century the Sentencing Guidelines have been in effect, we have sought to effectuate the guidelines’ purposes by requiring the district court to utilize the presumptive sentence in the usual case.7 We hold, therefore, that like the sentencing guidelines systems at issue, in Blakely and Booker, under the Minnesota Sentencing Guidelines imposition of the presumptive sentence is mandatory absent additional findings.8
It follows from this holding that for purposes of the constitutional rule that has evolved in the Apprendi line of cases, for felonies other than first-degree murder9 the presumptive sentence prescribed by the Minnesota Sentencing Guidelines is “the maximum sentence a judge may impose solely on the basis of facts reflected in the jury verdict or admitted by the defendant.” Blakely v. Washington, 124 S.Ct. at 2537 (emphasis omitted). An upward durational departure from the presumptive sentence, based on findings made by the district court, violates the Sixth Amendment right to trial by jury. Apprendi v. New Jersey, 530 U.S. at 490, 120 S.Ct. 2348; Blakely v. Washington, 124 S.Ct. at 2537. It is irrelevant whether the judicially determined facts require a sentencing departure, as under the repeat sex offender statute, or merely allow a departure, as under the guidelines. Blakely, 124 S.Ct. at 2538 n. 8. In either case, the court finds facts beyond the elements of the offense, and the verdict or guilty plea *142alone does not authorize the enhanced sentence. Id. We note that Blakely expressly permits a defendant to either stipulate to relevant facts or consent to judicial fact-finding regarding sentencing factors. Id. at 2541.
II.
The state also makes the argument that Blakely does not apply to sentencing under the Sentencing Guidelines because Minnesota’s guidelines are not statutory. The state contends that the legislature has created only one set of statutory máxi-mums. Unlike the statutory presumptive sentences enacted by the Washington Legislature that were at issue in Blakely, the state argues, the Minnesota Sentencing Guidelines simply reflect the combined wisdom of the various stakeholders in the criminal justice system who serve on the Commission, none of whom is appointed by the legislature. See Minn.Stat. § 244.09, subd. 2 (2004) (prescribing makeup of Commission).
The state made this argument before the Supreme Court’s decision in Booker. There the Court held that the fact the Federal Sentencing Guidelines were promulgated by the Sentencing Commission rather than by Congress “lacks constitutional significance.” United States v. Booker, 125 S.Ct. at 752. The Court reasoned that regardless of whether Congress or a commission determined that a particular fact must be proved in order to impose an enhanced sentence, the principles behind the jury-trial right are equally applicable. Id. at 752-53.
The same rationale applies to the Minnesota Sentencing Guidelines; the fact they were promulgated by the Commission rather than by the legislature is not relevant to the constitutional analysis. We note that the legislature created the Commission and outlined in broad strokes what the guidelines would ultimately look like. Minn.Stat. § 244.09, subds. 1, 5 (2004). Further, the legislature retained the power to reject the original guidelines promulgated by the Commission and to reject any modifications the Commission makes to the guidelines. Minn.Stat. § 244.09, subds. 11, 12 (2004). We conclude, therefore, that the state’s statutory argument lacks merit.
III.
In the present case, under Ap-prendi • and Blakely, the maximum sentence the district court could have imposed for Shattuck’s first-degree criminal sexual conduct conviction, based on the jury verdict alone, is the presumptive sentence of 161 (156-166) months’ imprisonment. Minn. Sent. Guidelines II.B.2, IV. When the court determined that aggravating factors existed that would provide grounds for an upward departure under the Sentencing Guidelines and imposed the mandatory minimum 30-year sentence pursuant to Minn.Stat. § 609.109, subd. 4, it violated Shattuck’s Sixth Amendment right to have a jury make that determination using a reasonable-doubt standard. We therefore hold that the upward departure from the presumptive sentence is unconstitutional. Because section 609.109, subdivision 4, and Minn. Sent. Guidelines II.D authorize the district court to make such an unconstitutional upward durational departure upon finding an aggravating factor without the aid of a jury, we hold that the statute is facially unconstitutional and section II.D of the guidelines is unconstitutional as applied.10 The statute is uncon*143stitutional in its entirety because without the unconstitutional provision it is incomplete and incapable of being executed in accordance with legislative intent. See Minn.Stat. § 645.20 (2004). This is so because in it, the legislature expressly conditioned the imposition of a 30-year sentence on a judicial finding that Blakely does not permit a sentencing judge to make: that “the crime involved an aggravating factor that would provide grounds for an upward departure under the Sentencing Guidelines * * *.” Minn.Stat. § 609.109, subd. 4(2)(i) (2004). Minnesota Sentencing Guidelines II.D is unconstitutional insofar as it permits an upward durational departure based on judicial findings.11
IV.
Having determined that Shattuck’s enhanced sentence is unconstitutional, we turn to the question of the appropriate remedy. The answer to this question depends, at least in part, on whether the unconstitutional provision of Minn. Sent. Guidelines II.D can be severed from the remainder of the guidelines.
A. Severability
When a court determines that a law is unconstitutional, it must invalidate only as much of the law as is necessary to eliminate the unconstitutionality. Chapman v. Comm’r of Revenue, 651 N.W.2d 825, 836 (Minn.2002) (citing Archer Daniels Midland Co. v. State, 315 N.W.2d 597, 600 (Minn.1982)). “We look first at the intent of the legislature to fashion a remedy consistent with that intent.” Id. Our primary goal in determining a remedy is, insofar as possible, to effectuate the intent of the legislature had it known that a provision of the law was invalid. Johnson Bros. Wholesale Liquor Co. v. Comm’r of Revenue, 402 N.W.2d 791, 793 (Minn.1987).
Minnesota Statutes § 645.20 states that absent a provision in the law to the contrary, the provisions of all laws are severable. If any provision of a law is found to be unconstitutional, “the remaining provisions of the law shall remain valid” unless the court makes either of two findings: (1) the valid provisions “are so essentially and inseparably connected with, and so dependent upon, the void provisions” that the court cannot presume the remaining valid provisions would have been enacted without the void one; or (2) the remaining valid provisions, standing alone, are incomplete and incapable of being executed in accordance with legislative intent. Id. We have emphasized that while we can strike a severable provision of a law if found to be unconstitutional, “we cannot add language to a statute in order to render it constitutionally permissible.” *144Chapman, 651 N.W.2d at 836 (quoting McGuire v. C & L Restaurant, Inc., 346 N.W.2d 605, 614 (Minn.1984)).
Minnesota Statutes § 244.09, subdivision 5, states that the Sentencing Guidelines are “a procedure based on state public policy to maintain uniformity, proportionality, rationality, and predictability in sentencing.” The Sentencing Guidelines themselves state that the purpose of the guidelines “is to establish rational and consistent sentencing standards which reduce sentencing disparity and ensure that sanctions following conviction of a felony are proportional to the severity of the offense of conviction and the extent of the offender’s criminal history.” Minn. Sent. Guidelines I. We have said that the guidelines were created to assure uniformity, proportionality, rationality, and predictability in sentencing. State v. Misquadace, 644 N.W.2d 65, 68 (Minn.2002) (citing Minn.Stat. § 244.09, subd. 5(2)). See also State v. Zeimet, 696 N.W.2d 791, 796 (Minn.2005) (stating that sentencing guidelines were created to assure equity in sentencing).12
In light of the overriding purposes of the Sentencing Guidelines system, we conclude that the unconstitutional portion of Minn. Sent. Guidelines II.D may be severed from the remaining provisions of the guidelines. Section II.D is unconstitutional only insofar as it allows the district court to impose an upward durational departure based on the court’s own findings. We do not believe that the remaining provisions of the Sentencing Guidelines are “so essentially and inseparably connected with, and so dependent upon” the unconstitutional provision allowing a judge to make findings which would justify an upward durational departure that the remaining provisions would not have been enacted without it. Minn.Stat. § 645.20.
We base this conclusion on a number of considerations. First, the Blakely decision narrowly focuses on the procedure of judge-determined upward departures from the presumptive sentence, not the substance or other procedural aspects of determinate sentencing. The Court expressly did not find determinate sentencing schemes unconstitutional, and stated that Blakely was concerned only with “how [determinate sentencing] can be implemented in a way that respects the Sixth Amendment.” 124 S.Ct. at 2540.
Second, to rule that section II.D cannot be severed from the remainder of the Sentencing Guidelines is to effectuate a return to an indeterminate sentencing system, in significantly different form than that which existed before the legislature supplanted it with a determinate Sentencing Guidelines system in 1978.
Until the advent of the Sentencing Guidelines, except for certain mandatory sentences such as for first-degree murder, “the length of a sentence was left almost entirely to the sentencing judge’s discretion, within the maximum terms established by the legislature” and constitutional limitations. 9 Henry W. McCarr & Jack S. Nordby, Minnesota Practice — Criminal Law & Procedure § 36.1 (3d ed.2001). As long as the sentence was authorized by law, it was not subject to appellate review; relief could only be had through the parole board. State v. Gamelgard, 287 Minn. 74, *14577-78, 177 N.W.2d 404, 407 (1970); State v. Dinneen, 289 Minn. 250, 259, 184 N.W.2d 16, 22 (1971). For felonies other than first-degree murder, a judge who chose to impose a prison sentence could either sentence the defendant to a maximum term of years selected by the court or to an indeterminate term that was deemed to be for the statutory maximum for the offense. Minn.Stat. § 609.10(2), (3) (1976). The parole board had broad authority to parole or discharge a defendant sentenced to prison, without regard to the length of the sentence. Minn.Stat. § 609.12, subd. 1 (1976).
Under the current statutory framework, the parole board that previously determined an inmate’s actual release date no longer exists, and the Commissioner of Corrections’ parole authority applies only to individuals sentenced before the Sentencing Guidelines took effect in 1980. Minn.Stat. §§ 243.05, subd. 1; 244.08, subd. 1 (2004). To strike down the Sentencing Guidelines regime in its entirety, as the dissent proposes, would give judges the discretion to impose a fixed prison sentence at any point within the statutory range for the particular offense.13 Minn. Stat. § 609.10, subd. 1(2) (2004). Thus, under the dissent’s proposed remedy, the judge at sentencing would both select a sentence within a broad range, and effectively determine the defendant’s actual release date.14 The representatives of the people have never voted for the indeterminate sentencing system the dissent proposes. To the extent it might be said that the legislature would not have enacted a determinate guidelines system without provision for upward durational departures, there is nothing to suggest that the legislature would have enacted the dissent’s proposed system.
To invalidate the Sentencing Guidelines system would also be contrary to the express sentencing policy of this state of maintaining uniformity, proportionality, and predictability in sentencing. Minn. Stat. § 244.09, subd. 5. A major purpose of the guidelines’ enabling statute was to reduce judges’ sentencing discretion, thus promoting greater uniformity of sentences. Richard S. Frase, The Role of the Legislature, The Sentencing Commission, and Other Officials Under the Minnesota Sentencing Guidelines, 28 Wake Forest L.Rev. 345, 347 (1993). There can be no doubt that complete invalidation of the Sentencing Guidelines would disserve the goal of uniformity in felony sentencing and would make sentencing in Minnesota more unpredictable.
The state argues that without sufficient provision for upward departures to maintain proportionality in sentencing, the Sentencing Guidelines would never have become law. The argument is based on the veto of an earlier version of determinate *146sentencing by then-Governor Wendell Anderson in 1976. The state asserts that the Governor vetoed the bill because he disagreed with the omission of extended term provisions for serious offenders, citing Research Project: Minnesota Sentencing Guidelines, 5 Hamline L.Rev. 292, 304 (1982). But this was not the reason for the veto. Governor Anderson vetoed the bill because its provision for extended terms for chronic dangerous offenders inadvertently failed to define “extended term.” Veto Message, 4 Journal of House of Representatives 6640-41 (69th Minn.Legis. Apr. 13, 1976). One governor’s veto of different legislation, followed by enactment of a commission-based Sentencing Guidelines system by a different legislature and signed by a different governor, is not helpful in determining legislative intent.
Proportionality in sentencing is not dependent upon the availability of upward durational departures from the presumptive sentence. Sentencing proportionality requires that more severe sanctions be imposed for more serious offenses and offenders. Kay A. Knapp, Impact of the Minnesota Sentencing Guidelines on Sentencing Practices, 5 Hamline L.Rev. 237, 247 (1982). The Sentencing Guidelines Grid “provides the primary mechanism for achieving proportionality in sentencing.” Id. While the mechanism for departing from the presumptive sentence further affects proportionality, id., retaining the Sentencing Guidelines while striking down that unconstitutional mechanism with respect to upward durational departures better serves the goal of proportionality than invalidating the Sentencing Guidelines in their entirety. In this regard, we note that the sentences provided in the grid “are presumed to be appropriate for every case,” and that departures are intended to apply to only a small number of cases.15 Minn. Sent. Guidelines II.D, II.D.01 cmt.; State v. Misquadace, 644 N.W.2d at 68.
We conclude that severing the unconstitutional portion of Minn. Sent. Guidelines II.D from the remainder of the guidelines best effectuates legislative intent. Severance of section II.D does the least damage, in terms of both keeping a sentencing structure in place close to what the legislature enacted, and the judiciary refraining from taking an active role in creating a sentencing scheme for the state. With the exception of that portion of section II.D, therefore, we leave the Sentencing Guidelines intact.
B. The Booker Remedy
The state urges us to follow the lead of the Supreme Court in Booker and modify the Minnesota Sentencing Guidelines to make them advisory. In Booker, the Court answered the question of remedy by finding the provision of the federal Sentencing Act that made the Federal Sentencing Guidelines mandatory to be “incompatible” with its constitutional holding that the federal guidelines are subject to Sixth Amendment jury-trial requirements, and severed that and another statutory provision relating to standards of review. 125 S.Ct. at 756-57, 764. The Court then required federal courts to consider guidelines ranges in imposing sentence, id. at 757, 767, and adopted a standard of unreasonableness for reviewing sentences, id. at 765. The Court based its holding on the determination that Congress would have preferred total invalidation of the Sentenc*147ing Act to engrafting a jury-trial requirement onto it, and would have preferred the Court’s remedy to total invalidation. Id. at 758-59.
The state asserts that the Booker holding is applicable to the Minnesota Sentencing Guidelines and legislative intent. The state proposes that two provisions of the Sentencing Guidelines be severed: the requirement of section II.D that the sentencing judge “shall utilize the presumptive sentence,” and section 1.4 in its entirety (“While the sentencing guidelines are advisory to the sentencing judge, departures from the presumptive sentences established in the guidelines should be made only when substantial and compelling circumstances exist.”).
We decline to modify the guidelines as the state requests. Because Booker was decided on purely federal law grounds, it does not mandate a similar result here. The Federal Sentencing Guidelines system is a complex one that differs significantly from Minnesota’s. More important, the Court’s approach to severability in Booker is far different than the traditional, deferential approach taken under Minnesota law. See Booker, 125 S.Ct. at 777 (Stevens, J., dissenting) (describing majority’s severability approach as “entirely new law”).
To accept the state’s invitation would effectively return felony sentencing in Minnesota to an indeterminate sentencing system. It would also require us to invalidate two provisions of the Sentencing Guidelines that suffer from no constitutional infirmity. It is not our role to choose among various provisions of the Sentencing Guidelines and select a sentencing system for this state.16
C. Other Remedies
In the earlier order in this case, we directed the parties to address the question whether this court has the inherent authority to authorize the use of sentencing juries and a bifurcated trial process. State v. Shattuck, 689 N.W.2d at 786. The parties agree that the court has the power to authorize both procedures.
“The inherent power of this court includes ‘the right to enable [the court] to administer justice whether any previous form of remedy has been granted or not.’ ” State v. Erickson, 589 N.W.2d 481, 485 (Minn.1999) (brackets in original) (quoting In re Clerk of Lyon County Court’s Compensation, 308 Minn. 172, 176, 241 N.W.2d 781, 784 (1976), in turn quoting In re Greathouse, 189 Minn. 51, 55, 248 N.W. 735, 737 (1933)). The authority to regulate matters of court procedure arises from the court’s inherent judicial powers. State v. Johnson, 514 N.W.2d 551, 553 (Minn.1994) (citing State v. Willis, 332 N.W.2d 180, 184 (Minn.1983)). Because the court’s inherent authority extends only to its unique judicial functions, we “proceed cautiously in exercising that authority in order to respect the equally unique authority of the executive and legislative branches of government over their consti*148tutionally authorized functions.” State v. C.A., 304 N.W.2d 353, 358-59 (Minn.1981) (citations omitted). In the area of sentencing, both the legislature and the judiciary-exercise constitutionally authorized functions. The power to fix the limits of punishment for criminal acts lies with the legislature, but the imposition of a sentence in a particular case within those limits is a judicial function. State v. Misquadace, 644 N.W.2d at 68; State v. Olson, 325 N.W.2d 13, 17-18 (Minn.1982).
While this court has the authority to establish procedures to apply the requirements of Apprendi and Blakely to sentencing in Minnesota, we leave to the legislature the task of deciding how the Sentencing Guidelines system should be altered to comport with those cases. It is the legislature that created the Sentencing Guidelines system and retains authority over its development. For us to engraft sentencing-jury or bifurcated-trial requirements onto the Sentencing Guidelines and sentencing statutes would require rewriting them, something our severance jurisprudence does not permit. See Chapman v. Comm’r of Revenue, 651 N.W.2d at 836.
We reverse the decision of the court of appeals and remand this case to the district court for resentencing consistent with this opinion.17
Reversed and remanded for resentenc-ing.
. Under the guidelines currently in force, the offenses are severity level nine and the presumptive sentence is the same.
. The statute provides, in relevant part:
The court shall commit a person to the commissioner of corrections for not less than 30 years * * * ⅛
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(2) the court determines on the record at the time of sentencing that:
(i) the crime involved an aggravating factor that would provide grounds for an upward departure under the Sentencing Guidelines other than the aggravating factor applicable to repeat criminal sexual conduct convictions; and
(ii) the person has a previous sex offense conviction under sections 609.342, 609.343, or 609.344.
Minn.Stat. § 609.109, subd. 4(a) (2004).
. We recently overruled Smith in light of Blakely. State v. Leake, 699 N.W.2d 312, 323 (Minn.2005).
. The forms of first- and second-degree criminal sexual conduct to which the repeat sex offender statute applies are all severity level eight and nine offenses under the Sentencing Guidelines and carry presumptively executed sentences. See Minn.Stat. § 609.109, subd. 4(a)(1); Minn. Sent. Guidelines IV, V. Thus, the constitutionality of upward dispositional departures under the Sentencing Guidelines is not at issue in this case.
. This provision was enacted following our holding, in State v. Givens, 544 N.W.2d 774, 777 (Minn. 1996), that “defendants may relinquish their right to be sentenced under the guidelines,” so long as the waiver was knowing, intelligent, and voluntary. We subsequently concluded that the fairest reading of this provision of the 1997 amendment is that the legislature removed whatever "right” a defendant might have to sentencing under the guidelines. State v. Misquadace, 644 N.W.2d 65, 70-71 (Minn.2002). We have also noted that although the legislature in the 1997 amendment stated for the first time that the guidelines are based on state public policy to maintain sentencing uniformity, proportionality, rationality and predictability, these principles have been part of the Sentencing Guidelines’ "Statement of Purpose and Principles” since their inception. Hutchinson v. State, 679 N.W.2d 160, 164 (Minn.2004) (citing Minn. Sent. Guidelines I). We have further emphasized that these overriding principles apply in "all sentencing.” Id. (emphasis in original) (quoting Misquadace, 644 N.W.2d at 71).
. By statute, the presumptive range may consist of an increase or decrease of up to 15% in the presumptive, fixed sentence. Minn.Stat. § 244.09, subd. 5. In 2005, the legislature amended this provision to provide for an increase of 20% from the fixed sentence and a decrease of 15%. Act of June 2, 2005, ch. 136, art. 16, § 1, 2005 Minn. Laws-,-.
. The district court’s sentencing discretion under the Sentencing Guidelines is further constrained by the statutory requirement that the court make written findings of fact as to the reasons for departure from the presumptive sentence and the statute instituting appellate review of sentences. Minn.Stat. §§ 244.10, subd. 2; 244.11 (2004).
. In State v. Misquadace, we noted that under the federal and Washington guidelines systems, like Minnesota’s, the 'primary relevant sentencing criteria [are] the offense of conviction and the offender’s criminal history.” 644 N.W.2d 65, 68 (Minn.2002) (citations omitted). The Washington sentencing scheme at issue in Blakely is similar to Minnesota's in several material respects. It required the district court to impose a sentence within a range set out in a sentencing grid unless the court found "substantial and compelling” reasons to depart. Wash. Rev.Code §§ 9.94A.120G), (2); 9.94A.310 (2000). Written findings for a departure were required, and the guidelines provided a nonexhaustive list of factors for departure. Wash. Rev.Code §§ 9.94A. 120(3); 9.94A.390 (2000). Further, Washington case law like ours prohibits using factors for a sentencing departure that have already been taken into account in computing the presumptive ("standard range”) sentence. State v. Gore, 143 Wash.2d 288, 21 P.3d 262, 277 (2001) (quoted and cited in Blakely v. Washington, 124 S.Ct. at 2537, for the proposition that had the judge imposed the enhanced sentence solely on the basis of Blakely’s guilty plea, he would have been reversed).
.First-degree murder is excluded from the Sentencing Guidelines because it carries a mandatory sentence of life imprisonment. Minn. Sent. Guidelines H.A.; Minn.Stat. § 609.185(a) (2004).
. The traditional rule is that a law is facially unconstitutional only if it is unconstitutional in all of its applications. See United States v. Salerno, 481 U.S. 739, 745, 107 S.Ct 2095, 95 *143L.Ed.2d 697 (1987) (to succeed in facial challenge, challenger "must establish that no set of circumstances exists under which the Act would be valid”). Appellant has not demonstrated that Minn. Sent. Guidelines II.D is unconstitutional in all of its applications, because a section not before us today, which provides for imposition of an upward departure based on the fact of a prior conviction, could be determined to be constitutional. See Minn. Sent. Guidelines II.D.2.b(3) (listing as aggravating factor fact that defendant's current and past felony convictions are for criminal sexual conduct or offense in which victim was otherwise injured). The presence of this aggravating factor is insufficient to trigger sentencing under the repeat sex offender statute. Minn. Stat. § 609.109, subd. 4(a)(2)(i) (2004).
. We note that the legislature has recently amended section 609.109, subdivision 4, and has adopted a revision of Minn. Sent. Guidelines II.D that was recommended by the Commission. Act of June 2, 2005, ch. 136, art. 16, §§ 9, 14, 2005 Minn. Laws -, -; see Minn. Sent. Guidelines Comm'n, Report to the Legislature 11-12 (Jan.2005). The validity of those provisions is not before us here.
. Drawing on the statute, section I of the guidelines and other sources, we have characterized Minnesota's Sentencing Guidelines system as a commission-based system the goals of which are "to assure public safety, promote uniformity and proportionality in sentencing, provide greater honesty or 'truth in sentencing,’ and coordinate sentencing practices within correctional resources." Zeimet, 696 N.W.2d at 796 (quoting Taylor v. State, 670 N.W.2d at 586).
. In the case of first-degree criminal sexual conduct, for example, it is conceivable that one judge could impose a minimal year-and-a-day prison sentence for an individual who sexually penetrates an infant, and another judge could sentence an 18-year-old to a 30-year prison term for having sexual intercourse with a nearly 16-year-old non-relative who resides in the same home and who in fact consented but by law is deemed incapable of consent. See Minn.Stat. §§ 609.342, subds. 1(a) and (g), 2(a); 609.341, subd. 15(3) (2004).
. The only reduction of a prison sentence currently provided by statute is good time earned by the defendant. See Minn.Stat. §§ 244.04; 244.05, subd. 1 (2004). Good-time reduction of a prison sentence was available in addition to the opportunity for parole before the Sentencing Guidelines were adopted. See Minn.Stat. § 243.18 (1976) (repealed 1978). It is not clear whether the dissent’s proposed remedy would include elimination of appellate review of sentences, another significant limitation on the discretion of the district court.
. In 2003, the last year for which statistics have been reported, the number of aggravated sentencing departures, both durational and dispositional, constituted 7.3% of felony sentences. Minn. Sent. Guidelines Comm’n, The Impact of Blakely v. Washington on Sentencing in Minnesota: Long Term Recommendations 8 (Sept. 30, 2004).
. We note that the revision of Minn. Sent. Guidelines II.D that the legislature adopted in 2005, see footnote 10, supra, includes language that a sentence outside the applicable range on the grid "is not controlled by the guidelines, but rather, is an exercise of judicial direction,” and that aggravating departure factors "are advisory only.” Minn. Sent. Guidelines Comm’n, Report to the Legislature 11-12 (Jan.2005). We further note that this provision "is effective the day following final enactment” and thus has only prospective application. Act of June 2, 2005, ch. 136, art. 16, § 14, •— Minn. Laws. -, -. By contrast, other provisions of the act affecting sentencing departures are "effective the day following final enactment and appl[y] to sentencing hearings, sentencing rehearings, and sentencing departures sought on or after that date.” Id., §§ 3-6 (emphasis added).
. We note that the legislature has recently enacted significant new requirements for aggravated sentencing departures, including sentencing juries and bifurcated trials, and that these changes apply both prospectively and to resentencing hearings. Act of June 2, 2005, ch. 136, art. 16, §§ 3-6, 2005 Minn. Laws -, -. We express no opinion about these recent changes, and do not foreclose the district court from considering any constitutionally applicable and/or available laws on remand.