The defendant, Melvin Lewis, pled guilty to armed robbery, MCL 750.529; MSA 28.797, and felony-firearm, MCL 750.227b; MSA 28.424(2). When this case was first appealed in 1982, this Court remanded the felony-firearm issue under People v Johnson, 411 Mich 50; 303 NW2d 442 (1981), to allow the prosecutor an opportunity to show an adequate factual basis for aiding and abetting.
On remand the prosecutor was unable to meet his burden, and the trial court dismissed the felony-firearm count. The prosecutor then moved for resentencing on the armed robbery conviction, arguing that the sentence on that count had been tailored to accommodate the mandatory two-year sentence for felony-firearm. The court agreed with the prosecutor, ruling that it had originally operated under a misconception of the law regarding adequacy of proofs for the felony-firearm convic*702tion, and added two years to the armed robbery sentence.
The defendant now appeals, arguing that the court erred by resentencing him. We agree and amend the sentence to its original form.
The trial court is without power to set aside a valid sentence and impose a new one. People v Whalen, 412 Mich 166, 169; 312 NW2d 638 (1981). This case does not fall within any of the Whalen exceptions. Although the trial court was originally mistaken on the felony-firearm count, this did not taint the armed robbery conviction or sentence. Standing alone, the armed robbery sentence was valid, even though the sentencing judge would have preferred a more severe sentence. Felony-firearm is a separate and distinct offense from other simultaneous charges. Wayne County Prosecutor v Recorder’s Court Judge, 406 Mich 374, 391; 280 NW2d 793, app dis 444 US 948; 100 S Ct 418; 62 L Ed 2d 317 (1979). Its sentence is intended to be cumulative to, and not a substitute for, sentences for other offenses. Id.
The second sentence is vacated and the original sentence, 16 months to 10 years, reinstated.