diff --git a/ili9341/ili9341.go b/ili9341/ili9341.go
index 4b8f133..421b3d2 100644
--- a/ili9341/ili9341.go
+++ b/ili9341/ili9341.go
@@ -320,10 +320,16 @@ func (d *Device) SetRotation(rotation drivers.Rotation) error {
 // SetScrollArea sets an area to scroll with fixed top/bottom or left/right parts of the display
 // Rotation affects scroll direction
 func (d *Device) SetScrollArea(topFixedArea, bottomFixedArea int16) {
+	if d.height < 320 {
+		// The screen doesn't use the full 320 pixel height.
+		// Enlarge the bottom fixed area to fill the 320 pixel height, so that
+		// bottomFixedArea starts from the visible bottom of the screen.
+		bottomFixedArea += 320 - d.height
+	}
 	cmdBuf[0] = uint8(topFixedArea >> 8)
 	cmdBuf[1] = uint8(topFixedArea)
-	cmdBuf[2] = uint8(d.height - topFixedArea - bottomFixedArea>>8)
-	cmdBuf[3] = uint8(d.height - topFixedArea - bottomFixedArea)
+	cmdBuf[2] = uint8((320 - topFixedArea - bottomFixedArea) >> 8)
+	cmdBuf[3] = uint8(320 - topFixedArea - bottomFixedArea)
 	cmdBuf[4] = uint8(bottomFixedArea >> 8)
 	cmdBuf[5] = uint8(bottomFixedArea)
 	d.sendCommand(VSCRDEF, cmdBuf[:6])
diff --git a/st7735/st7735.go b/st7735/st7735.go
index fd0829b..f9521cd 100644
--- a/st7735/st7735.go
+++ b/st7735/st7735.go
@@ -235,6 +235,8 @@ func (d *Device) setWindow(x, y, w, h int16) {
 
 // SetScrollWindow sets an area to scroll with fixed top and bottom parts of the display
 func (d *Device) SetScrollArea(topFixedArea, bottomFixedArea int16) {
+	// TODO: this code is broken, see the st7789 and ili9341 implementations for
+	// how to do this correctly.
 	d.Command(VSCRDEF)
 	d.Tx([]uint8{
 		uint8(topFixedArea >> 8), uint8(topFixedArea),
diff --git a/st7789/st7789.go b/st7789/st7789.go
index 8a145e4..96b1232 100644
--- a/st7789/st7789.go
+++ b/st7789/st7789.go
@@ -554,9 +554,16 @@ func (d *Device) IsBGR(bgr bool) {
 
 // SetScrollArea sets an area to scroll with fixed top and bottom parts of the display.
 func (d *Device) SetScrollArea(topFixedArea, bottomFixedArea int16) {
+	if d.height < 320 {
+		// The screen doesn't use the full 320 pixel height.
+		// Enlarge the bottom fixed area to fill the 320 pixel height, so that
+		// bottomFixedArea starts from the visible bottom of the screen.
+		bottomFixedArea += 320 - d.height
+	}
+	verticalScrollArea := 320 - topFixedArea - bottomFixedArea
 	copy(d.buf[:6], []uint8{
 		uint8(topFixedArea >> 8), uint8(topFixedArea),
-		uint8(d.height - topFixedArea - bottomFixedArea>>8), uint8(d.height - topFixedArea - bottomFixedArea),
+		uint8(verticalScrollArea >> 8), uint8(verticalScrollArea),
 		uint8(bottomFixedArea >> 8), uint8(bottomFixedArea)})
 	d.startWrite()
 	d.sendCommand(VSCRDEF, d.buf[:6])