The appellant challenges the denial of a petition for a writ of mandamus, by which he contested disciplinary action taken by the Department of Corrections (the department). The appellant is a prison inmate who was disciplined for shaving his head, and the disciplinary team found this to be a violation of the institution’s barber shop rule. After the appellant petitioned for mandamus the department acknowledged that the barber shop rule should not have been applied to an inmate who shaved his own head, but the department asserted that the appellant was nevertheless properly disciplined because another institutional rule precluded the appellant from shaving his head. Although the court accepted the department’s position in denying relief, in his pleadings below the appellant described evidence which he attempted to present at the disciplinary hearing and which was not allowed because it was not pertinent to a violation of the barber shop rule. Because this evidence addresses the enforcement of the rule upon which the department now relies, this change in the basis of the discipline adversely impacts the appellant’s due process rights. The appealed *94order is therefore reversed, and the case is remanded.