¶1 — We must decide whether first degree rape of a child and first degree statutory rape are legally comparable crimes. We conclude they are and affirm Dan Stockwell’s life sentence as a persistent offender.
Chambers, J.I
¶2 In 1986, Stockwell pleaded guilty to one count of first degree statutory rape. The information filed in the 1986 case charged:
*396That DANIEL J. STOCKWELL, in Pierce County, Washington, during the period between February 1, 1985 and March 31, 1985, did unlawfully and feloniously being over the age of 13 years, engage in sexual intercourse with [CS], who was less than 11 years old, contrary to RCW 9A.44,070[ (1986)], and against the peace and dignity of the State of Washington.
Clerk’s Papers (CP) at 62-63.1 The probable cause affidavit additionally revealed that CS was eight years old and that “the defendant, her mother’s boyfriend, on numerous occasions, engaged in sexual intercourse with her.” CP at 64. Stockwell’s statement on plea of guilty acknowledged that he was over 13, CS was under 11, and that they had had intercourse. Nowhere in the charging or sentencing documents or in the guilty plea does it affirmatively state that Stockwell was not married to eight-year-old CS, though it does establish he was 34 years old at the time.2
¶3 Later, Stockwell married CS’s mother. Then, in 2004, Stockwell was tried and convicted of first degree child molestation and attempted child molestation of two of his wife’s granddaughters. Given his prior rape conviction, the State successfully sought a life sentence under the Persistent Offender Accountability Act (POAA), former RCW 9.94A.030(32)(b) (2002), recodified as RCW 9.94A-.030(33)(b); RCW 9.94A.570.
¶4 Stockwell appealed his sentence, arguing that his prior offense, first degree statutory rape, is neither listed as nor comparable to a strike offense, and thus he was not eligible for a life sentence. The Court of Appeals affirmed the trial court. We accepted review.
*397II
¶5 Since only questions of law are before us, our review is de novo. Dep’t of Ecology v. Campbell & Gwinn, LLC, 146 Wn.2d 1, 9, 43 P.3d 4 (2002). The POAA requires a life sentence upon the second (or third) conviction for certain designated crimes or for crimes that are deemed “comparable” to those designated. RCW 9.94A.030(33). First degree rape of a child is a designated strike offense, but in 1986 no crime in Washington bore that name. See RCW 9.94A.030(33)(b)(i), .570. We turn first to whether rape of a child is legally comparable to first degree statutory rape.
¶6 We recently considered a similar question in In re Personal Restraint of Lavery, 154 Wn.2d 249, 111 P.3d 837 (2005). We reiterated that when “the elements of the foreign conviction are comparable to the elements of a Washington strike offense on their face, the foreign crime counts toward the offender score as if it were the comparable Washington offense.” Id. at 255 (citing State v. Morley, 134 Wn.2d 588, 605-06, 952 P.2d 167 (1998)). While Stockwell’s offense was not a foreign one, we will apply a similar approach here.
f 7 Thus, if the elements of the strike offense and the elements of the foreign (or prior) crime are comparable, the former (or prior) crime is a strike offense. Id. Legal comparability analysis is not an exact science, but when, for example, an out-of-state statute criminalizes more conduct than the Washington strike offense, or when there would be a defense to the Washington strike offense that was not meaningfully available to the defendant in the other jurisdiction or at the time, the elements may not be legally comparable. See Lavery, 154 Wn.2d at 256-57.
f8 Only one element concerns us here. The legislature has added a statutory element to first degree rape of a child: nonmarriage. RCW 9A.44.073(1). The former statutory rape statute, however, did not mention marriage. See former RCW 9A.44.070, repealed by Laws of 1988, ch. 145, *398§ 24(1).3 Stockwell argues that the modern statute criminalizes less conduct (by exempting sexual contact between spouses) and provides a defense (of marriage) that would not have been available under the prior law. The Court of Appeals rejected his claim because it found that nonmarriage was an implied, nonstatutory element of the crime of statutory rape and thus the elements were comparable. State v. Stockwell, 129 Wn. App. 230, 235, 118 P.3d 395 (2005).
f 9 In the 1980s, divisions of the Washington State Court of Appeals split on whether nonmarriage was an implied element of first degree statutory rape: Division Two finding it was, Division One finding it was not. State v. Bailey, 52 Wn. App. 42, 46-47, 757 P.2d 541 (1988), aff’d on other grounds, 114 Wn.2d 340, 787 P.2d 1378 (1990); State v. Hodgson, 44 Wn. App. 592, 599, 722 P.2d 1336 (1986), aff’d on other grounds, 108 Wn.2d 662, 740 P.2d 848 (1987).4
¶10 In Bailey, a defendant was charged with first degree statutory rape of a three-year-old child. The jury was instructed that if it could not reach a verdict on that charge, it could consider whether the defendant had committed indecent liberties as a lesser included offense. The jury returned a verdict for indecent liberties and Bailey appealed. Bailey argued that, per Hodgson, indecent liberties was not a lesser included offense of first degree statutory rape since indecent liberties contained an element not present in first degree statutory rape: nonmarriage.
*399¶11 Division Two disagreed. It concluded:
the analysis in Hodgson leads to absurd results. First, the Legislature cannot possibly have contemplated statutory rape in the first degree [as] being perpetrated on one’s spouse. In the unlikely event that a child of 10 years [old] or less establishes sufficient necessity to receive permission from the superior court to marry, it is inconceivable that the Legislature intended to criminalize consensual sexual intercourse between spouses, regardless of their ages. The fact that the Legislature did not expressly make nonmarriage an element of first degree statutory rape can lead to only one logical conclusion: the Legislature did not expect that children under the age of 10 would be marrying. Therefore, the only plausible reading of former RCW 9A.44.070 is to consider nonmarriage an implicit element of the crime.
Bailey, 52 Wn. App. at 46. We agree with. Division Two that it is simply inconceivable that the legislature would expect that children 10 years old or less would marry. Nonmar-riage is an implied element of the crime of first degree statutory rape.
¶12 Further, our purpose today is to determine what the legislature intended. Cf. State v. Calle, 125 Wn.2d 769, 777-78, 888 P.2d 155 (1995). The legislature added this comparability clause after a court declined to infer one. See State v. Delgado, 148 Wn.2d 723, 725, 63 P.3d 792 (2003); Laws of 2001, ch. 7, § 2(31)(b)(ii). Given the apparent impetus for adding a comparability clause to the POAA, given Bailey, and given the legislative history of these statutes, we hold as a matter of law that first degree statutory rape under former RCW 9A.44.070(1) and first degree rape of a child under RCW 9A.44.073(1) are comparable. See RCW 9.94A.030(33)(b), .570.5
*400III
¶13 Former first degree statutory rape and rape of a child in the first degree are comparable. Therefore, first degree statutory rape is a “strike” under the “two strikes” provision of the POAA. We affirm the Court of Appeals and affirm Stockwell’s life sentence.
Alexander, C.J., and C. Johnson, Madsen, Bridge, Owens, Fairhurst, and J.M. Johnson, JJ., concur.
At approximately the same time, Stockwell pleaded guilty to one count of indecent liberties against a different victim. After these two convictions, he received sex offender treatment. It appears that there are no intervening convictions.
In 1986, the age of consent to marry in Washington was 18. Laws of 1973, 1st Ex. Sess., ch. 154, § 26, codified as RCW 26.04.010. A marriage where one party is younger than 17 is simply void unless a trial judge finds a “necessity not to void it. Id.
The legislature created the current crime of first degree rape of a child in that same act. See Laws of 1988, ch. 145, § 2, codified as RCW 9A.44.073.
Stockwell asserts that this court has already found that rape of a child and statutory rape were not substantially similar in In re Personal Restraint of Thompson, 141 Wn.2d 712, 10 P.3d 380 (2000). We disagree. In Thompson, the petitioner pleaded guilty to a crime (rape of a child) that did not exist on the date of the conduct charged. This court vacated, tolled the statute of limitations, and allowed refiling of the charges under the correct statute. A judgment and sentence is clearly invalid on its face if it is for a crime that did not exist at the time. Id. at 719. The primary issue in Thompson was whether the defendant had waived the issue or invited the error by pleading guilty. While there was some discussion of the elements of the two crimes in the context of the statute of limitations and the appropriate scope of a superseding indictment, the parties did not appear to be disputing what the elements were, merely the consequences of them.
Before 2004, it was clear that prior crimes could also be factually comparable to strike offenses. Morley, 134 Wn.2d 588. Since we find that rape of a child and statutory rape are legally comparable, no fact finding is necessary. Therefore, we do not reach whether Blakely v. Washington, 542 U.S. 296, 124 S. Ct. 2531, 159 L. Ed. 2d 403 (2004) requires a jury trial to determine whether a prior offense is factually comparable.