An image forming apparatus includes a developer bearer and a toner pattern bearer rotatable in a given direction of rotation to bear an adjustment toner pattern formed with the developer bearer. A toner pattern detector detects an amount of reflection light reflected by the adjustment toner pattern on the toner pattern bearer. A controller performs an adjustment mode to convert the detected amount of reflection light into a toner adhesion amount of toner of the adjustment toner pattern adhered to the toner pattern bearer. The controller forms an adhesion amount suppressing toner image on an upstream region on the toner pattern bearer that is upstream from the adjustment toner pattern in the direction of rotation of the toner pattern bearer. The upstream region is defined by a circumferential length of the developer bearer in the direction of rotation of the toner pattern bearer.