Joseph Cantone appeals his sentence, following his guilty-plea conviction for conspiracy to distribute at least 50 grams of methamphetamine. Although Cantone concedes his sentence is reviewed for reasonableness under this court’s post-Booker precedent, e.g., United States v. Mares, 402 F.3d 511, 520 (5th Cir. 2005), he asserts the presumption-of-reasonableness standard is unconstitutional. Needless to say, absent changed, controlling authority, a panel of this court is bound by our circuit’s precedent. E.g., United States v. Short, 181 F.3d 620, 624 (5th Cir. 1999).

Cantone further contends his 210 month sentence, which was at the bottom of the guideline range, is unreasonable under 18 U.S.C. § 3553(a) because it is greater than necessary to achieve the sentencing goals. Cantone has not shown his sentence is unreasonable. See Mares, 402 F.3d at 519.

AFFIRMED.