Zhang Jian Long and Dongyan Huang appeal from their convictions, after pleading guilty, for violating, respectively, 18 U.S.C. § 2320(a) and 31 U.S.C. § 5324. They maintain that the district court1 erred in denying Mr. Zhang’s motion to suppress his pretrial statements and failed in its constitutional and statutory duty to provide them with an adequate interpreter at various hearings relating to their case.
As the government points out, however, the defendants in their written plea agreements waived their right to appeal, with certain exceptions. The defendants assert that their appeal should be allowed because the sentence is “unconstitutionally defective,” one of the exceptions to their appeal waivers. The infirmity in the defendants’ argument is that they point to no defect in the sentence: They maintain only that there was a constitutional defect in the proceedings that led up to the sentencing. The appeal is therefore barred unless the plea agreements and corresponding waivers were not knowing and voluntary, or a miscarriage of justice would occur if the waivers were enforced. See United States v. Andis, 333 F.3d 886, 889-92 (8th Cir.2003) (en banc).
The defendants do not maintain that they did not understand the appeal waiver or any other part of their plea agreements, which they initialed at the beginning of each paragraph and signed at the bottom. And after a careful review of the record, we conclude that the district court conducted the proceedings with a conscientious regard for defendants’ rights and that therefore the enforcement of the *115waiver could not result in a miscarriage of justice.
Accordingly, we dismiss the defendants’ appeals.