Chris Walker appeals his sentence of life imprisonment under 21 U.S.C. § 841 following his guilty plea conviction for conspiracy to distribute and possess with the *122 intent to distribute cocaine base, cocaine hydrochloride, and marijuana and possession with the intent to distribute cocaine base, cocaine hydrochloride, and marijuana. He argues that the district court erred in enhancing his sentence under § 841 based on his prior state conviction for distribution of marijuana because the conviction resulted from a plea of nolo contendere. Walker contends that an admission of guilt is necessary to constitute a conviction within the meaning of § 841.

This court need not address Walker’s contention, which seeks a construction of the § 841 enhancement provision. The district court rendered an alternative sentence after it properly calculated Walker’s guidelines range and imposed a sentence within the guidelines range. Thus, Walker’s sentence of life imprisonment founded on the guidelines is entitled to a presumption of reasonableness. See United States v. Alonzo, 435 F.3d 551, 554 (5th Cir. 2006). Nothing in the record indicates that the court committed procedural error in calculating the Guidelines, and the sentence is substantively reasonable. See Gall v. United States, — U.S. -, 128 S.Ct. 586, 597,169 L.Ed.2d 445 (2007). 1

Accordingly, the judgment of the district court is AFFIRMED.