The district court violated the Sixth Amendment by applying a mandatory version of the federal sentencing guidelines, which required it to enhance the defendant’s sentence beyond the statutory maximum based on facts not admitted to by him nor found by a jury beyond a reasonable doubt. United States v. Booker, — U.S. -, -, 125 S.Ct. 738, 756, 160 L.Ed.2d 621 (2005). The defendant raised and preserved the error at the time of sentencing and we cannot say this constitutional error was harmless beyond a reasonable doubt. See United States v. Haidley, 400 F.3d 642 (8th Cir. 2005). We therefore vacate the sentence and remand for resentencing.