STEPHANIE DAWKINS DAVIS, Circuit Judge. Defendant Idris Quintell Wilkes was convicted of being a felon in possession of a firearm in the district court for the Western District of Michigan. He received the mandatory minimum sentence of 15 years’ imprisonment under the Armed Career Criminal Act (ACCA), 18 U.S.C. § 924(e)(1), based on the district court’s determination that his four previous cocaine-related Michigan convictions met the definition of a “serious drug offense.” Wilkes contends, however, that Michigan law covers more cocainerelated substances than federal law in two ways: (1) Michigan’s law includes [123I] ioflupane and federal law does not, and (2) Michigan includes all the stereoisomers of cocaine and federal law does not. Accordingly, he argues that when the court applies the categorical approach under the ACCA, it must find that his prior convictions are not predicate serious drug offenses under the statute. The government maintains that the ACCA enhancement was properly applied because the state law is co-extensive with federal law, so there is no categorical mismatch.

Wilkes also argues that the district court improperly overruled his objection to the inclusion of proffer-protected information in the presentence report. According to the government, to the extent this error was raised below, it was harmless. And to the extent Wilkes raises new arguments to support this claim, he has failed to establish plain error.

For the reasons set forth below, we AFFIRM the decision of the district court in part and hold the appeal in abeyance in part, retaining jurisdiction to later resolve one of Wilkes’s two challenges to the ACCA enhancement.