Walter Alberto Mejia-Ruiz (Mejia) appeals his sentence following his guilty plea conviction for illegal reentry. He argues that the district court reversibly erred under United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), by sentencing him pursuant to a mandatory application of the Sentencing Guidelines. The Government concedes that Mejia has preserved this issue for appeal. The Government, however, has not shown beyond a reasonable doubt that the error was harmless. See United States v. Walters, 418 *992F.3d 461, 463-64 (5th Cir. 2005). Accordingly, Mejia’s sentence is vacated, and this case is remanded for resentencing.

CONVICTION AFFIRMED; SENTENCE VACATED; REMANDED FOR RESENTENCING.