Octavio Cruz Beltran pled guilty to possession of a firearm by an illegal alien. At sentencing, the district court overruled Beltran’s objections to the presentence report and sentenced him to forty-eight months in prison, a sentence within the Guidelines range. On appeal, Beltran contends that the sentence is unconstitutional because he was sentenced under a de facto mandatory Guidelines system. Accordingly, he asserts that his sentence, which was based on the judge’s factual findings rather than his admissions or jury findings, violated his Fifth and Sixth Amendment rights. We affirm,

Because Beltran did not raise this issue in the district court, our review is for plain error. United States v. Hughes, 401 F.3d 540, 547 (4th Cir. 2005). We have concluded that sentencing decisions made by the district court based upon the preponderance of the evidence comport with the Sixth Amendment. See United States v. Morris, 429 F.3d 65, 69 (4th Cir. 2005), cert. denied, — U.S. -, 127 S.Ct. 121, 166 L.Ed.2d 91 (2006). We review a sentence “to determine whether the sentence is within the statutorily prescribed range and is reasonable.” United States v. Moreland, 437 F.3d 424, 433 (4th Cir.), cert. denied, — U.S. -, 126 S.Ct. 2054, 164 L.Ed.2d 804 (2006). “[A] sentence within the proper advisory Guidelines range is presumptively reasonable.” United States v. Johnson, 445 F.3d 339, 341 (4th Cir. 2006). However, while a sentence outside the Guidelines range is not presumptively unreasonable, United States v. Green, 436 F.3d 449, 457 (4th Cir.), cert. denied, — U.S. -, 126 S.Ct. 2309, 164 L.Ed.2d 828 (2006), the further the sentencing court diverges from the Guidelines, the more compelling the reasons for the divergence must be. See Moreland, 437 F.3d at 434.

In light of our precedents, we find no merit to Beltran’s claims that he was sentenced under a mandatory system. See Rita v. United States, — U.S. -, 127 S.Ct. 2456, 2462, 168 L.Ed.2d 203 (2007) (upholding presumption of reasonableness). In addition, our review of the record shows that the district court properly applied our precedents and that the sentence is reasonable.

*463 We therefore affirm the sentence imposed by the district court. We dispense with oral argument, because the facts and legal contentions are adequately presented in the materials before the court and argument would not aid the decisional process.

AFFIRMED.