Sheila Trahan, federal prisoner # 13730-179, appeals the dismissal of her 28 U.S.C. § 2241 petition. Trahan pleaded guilty to being a felon in possession of a firearm in December 2002 and she was sentenced to a 120-month term of imprisonment. In a previous proceeding, the district court denied Trahan’s request for relief under 28 U.S.C. § 2255.

Trahan argues that she is entitled to a certificate of appealability (COA) on several claims that attack her conviction and her sentence. Because Trahan is proceeding under § 2241, however, she is not required *253 to obtain a COA in order to appeal the district court’s judgment. See Wesson v. U.S. Penitentiary Beaumont, Tx., 305 F.3d 343, 345 (5th Cir. 2002); Ojo v. INS, 106 F.3d 680, 681-82 (5th Cir. 1997).

Trahan’s § 2241-denominated petition raised an error that allegedly occurred at her sentencing. Therefore, the petition must be construed as sounding under 28 U.S.C. § 2255 unless Trahan establishes that her claim falls under the savings clause of 28 U.S.C. § 2255. See Christopher v. Miles, 342 F.3d 378, 381-82 (5th Cir. 2003). Because Trahan has not shown that the remedy provided under § 2255 is inadequate or ineffective to test the legality of her detention, she has not shown that she is entitled to bring a § 2241 petition under the savings clause of § 2255. See id. at 382; Tolliver v. Dobre, 211 F.3d 876, 877 (5th Cir. 2000).

Trahan had previously been denied relief under § 2255 and she had not obtained authorization to file a second or successive § 2255 motion. The district court therefore did not err in determining that it could not consider Trahan’s filing, which it properly construed as a § 2255 motion, because it was an unauthorized successive motion. See 28 U.S.C. §§ 2244(b)(3)(A), 2255. Accordingly, the judgment of the district court is

AFFIRMED.