MEMORANDUM **

Anthony Francis Book appeals from the 300-month sentence imposed following his guilty-plea conviction for conspiracy to possess methamphetamine with intent to distribute, in violation of 21 U.S.C. §§ 846 and 851. We have jurisdiction pursuant to 28 U.S.C. § 1291, and we affirm.

Book contends that the district court erred by failing to treat his two prior felony drug convictions as a single conviction for purposes of a sentence enhancement under 21 U.S.C. § 841(b)(1)(A), and that his overall sentence is substantively unreasonable. We decline to reach these contentions because Book pleaded guilty pursuant to a plea agreement in which he knowingly and voluntarily waived his right to appeal the sentence. See United States v. Bibler, 495 F.3d 621, 623-24 (9th Cir. 2007).

Book contends that his appeal waiver is inapplicable because the district court’s failure to treat his two prior felony drug convictions as a single conviction resulted in a disproportionate sentence that violates the “cruel and unusual punishment” clause of the Eighth Amendment. This contention fails. Although an appeal waiver will not apply if the sentence violates the Constitution, see id. at 624, Book’s sentence is well below the maximum term allowed and is not “so ‘grossly out of proportion to the severity of the crime’ as to shock our sense *723 of justice.” See United States v. Cupa-Guillen, 34 F.3d 860, 864 (9th Cir. 1994).

DISMISSED.