MEMORANDUM**
Jose Martinez challenges his sentence of twenty-four months for importation of marijuana in violation of 21 U.S.C. § 960. We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.
Martinez waived his right to appeal the district court’s two-point sentence enhancement under U.S. Sentencing Guideline § 3B1.4 by failing to raise it in his opening brief. ‘We ‘will not ordinarily consider matters on appeal that are not specifically and distinctly argued in appellant’s opening brief.’ ”1 We conclude that the circumstances of this case do not warrant deviating from this general rule.2
Although Martinez did not waive his right to challenge the constitutionality of 21 U.S.C. § 960,3 United States v. Mendoza-Paz4 forecloses his argument.5
His final argument, that § 960 requires knowledge of the type and quantity of the controlled substance at issue, fails as well. When drug quantity and type expose a defendant to a higher statutory maximum sentence than he would otherwise receive, knowledge and quantity must be charged and proved.6 In circumstances such as these, however, when drug quantity and type did not expose a defendant to a higher maximum sentence, no such requirement applies.7
Therefore, we AFFIRM.
AFFIRMED.
This disposition is not appropriate for publication and may not be cited to or by the courts of this circuit except as may be provided by Ninth Circuit Rule 36-3.
. United States v. Ullah, 976 F.2d 509, 514 (9th Cir.1992) (quoting Miller v. Fairchild Indus., Inc., 797 F.2d 727, 738 (9th Cir.1986)).
. See id. (describing exceptions to general rule).
. See United States v. Caperell, 938 F.2d 975, 977 (9th Cir.1991) (stating that a guilty plea does not waive jurisdictional challenges, such as challenges to a statute’s constitutionalily).
. 286 F.3d 1104 (9th Cir.), cert. denied - U.S. -, 123 S.Ct. 573, 154 L.Ed.2d 459 (2002).
. Id. at 1109-10.
. See United States v. Minore, 292 F.3d 1109, 1117 (9th Cir.2002), cert. denied - U.S. -, 123 S.Ct. 948, 154 L.Ed.2d 848 (2003).
. See id.; see also United States v. Carranza, 289 F.3d 634, 644 (9th Cir.), cert. denied - U.S. -, 123 S.Ct. 572, 154 L.Ed.2d 458 (2002).