Artemio Ramos, Jr., a federal prisoner proceeding pro se, appeals the district court’s denial of two belated post-conviction motions, in which he challenged the adequacy of the government’s notice to enhance his sentence pursuant to 21 U.S.C. § 851. However, the district court has rejected Ramos’s argument in at least one previous ruling that he did not appeal. As a result, Ramos’s argument is foreclosed by the law of the case doctrine. See United States v. Escobar-Urrego, 110 F.3d 1556, 1560 (11th Cir. 1997).

To the extent Ramos’s motions should have been construed as motions to vacate pursuant to 28 U.S.C. § 2255, we construe the notice of appeal here as an application for a certifícate of appealability (“COA”), see Pagan v. United States, 353 F.3d 1343, 1346 (11th Cir. 2003), and we find that Ramos has not met the applicable standard for obtaining a COA. See 28 U.S.C. § 2253(c)(2); Slack v. McDaniel, 529 U.S. 473, 484, 120 S.Ct. 1595, 146 L.Ed.2d 542 (2000). We further observe that Ramos has previously filed a § 2255 motion that was denied with prejudice, and he has not obtained the requisite permission from this Court to file a second or successive § 2255 motion. ■ See 28 U.S.C. § 2255(h). Accordingly, we affirm.

AFFIRMED.