The defendant in this case was sentenced prior to the United States Supreme Court decision in United States v. Booker, — U.S.-, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005). At the time of sentencing, the defendant raised and preserved error as to the constitutionality of the federal sentencing guidelines. During the sentencing hearing, the district court stated that if the federal sentencing regime were to change after Booker, the defendant could file a motion asking the district court to reconsider his sentence. It then sentenced the defendant to the minimum possible sentence under the applicable sentencing guidelines. Accordingly, we cannot say that the error in this case was harmless. We therefore vacate and remand for re-sentencing pursuant to United States v. Booker, — U.S.-, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005). See United States v. Haidley, 400 F.3d 642, 644-46 (8th Cir. 2005).