MEMORANDUM *

The Government appeals the district court’s sentencing for Gino Rodriquez’s conviction under 18 U.S.C. § 922(g)(1), felon in possession of a firearm, wherein the court found that Rodriquez’s criminal history did not subject him to a sentence enhancement under the Armed Career Criminal Act, 18 U.S.C. § 924 (“ACCA”). The Government argues that the court committed reversible error when it failed to consider Rodriquez’s 1986 California conviction in determining whether Rodriquez had been previously convicted of three drug-related crimes punishable by ten or more years imprisonment. See 18 U.S.C. § 924.

The Government concedes that it failed to raise the California conviction at sentencing and raises it now, for the first time, on appeal. Such a failure should normally result in waiver. However, because the issue before us is purely a question of law, we may exercise our discretion and rule on the matter. Jovanovich v. United States, 813 F.2d 1035, 1037 (9th Cir. 1987); see also United States v. DeSalvo, 41 F.3d 505, 510-11 (9th Cir. 1994). Exercising our discretion, we vacate the imposed sentence but decline to rule on the matter. Instead, we remand this case for resentencing before the district court, which should have had an opportunity to rule on this matter.

At sentencing, the district court must determine whether Rodriquez was convicted of a drug-related offense prior to his earliest Washington drug conviction. If so, Rodriquez’s initial Washington conviction would be punishable by a ten-year term of imprisonment. See Wash. Rev. Code §§ 9A.20.021(c); 69.50.401; 69.50.408. As a result, Rodriquez would have three previous convictions for serious drug offenses and must be sentenced to *749 serve a mandatory minimum sentence of 15 years. See 18 U.S.C. § 924(e).

VACATED and REMANDED.