diff --git a/containerbox.go b/containerbox.go
index 5a9899d..96c27b4 100644
--- a/containerbox.go
+++ b/containerbox.go
@@ -274,7 +274,7 @@ func (this *containerBox) doLayout () {
 	// offset the content bounds by the scroll so children can be positioned
 	// accordingly.
 	this.constrainScroll()
-	this.contentBounds = this.contentBounds.Sub(this.scroll).Sub(innerBounds.Min)
+	this.contentBounds = this.contentBounds.Add(this.scroll).Sub(innerBounds.Min)
 	
 	// arrange children
 	if this.layout != nil {
@@ -294,19 +294,19 @@ func (this *containerBox) constrainScroll () {
 	// X
 	if width <= innerBounds.Dx() {
 		this.scroll.X = 0
-	} else if this.scroll.X < 0 {
+	} else if this.scroll.X > 0 {
 		this.scroll.X = 0
-	} else if this.scroll.X > width - innerBounds.Dx() {
-		this.scroll.X = width - innerBounds.Dx()
+	} else if this.scroll.X < innerBounds.Dx() - width  {
+		this.scroll.X =  innerBounds.Dx() - width
 	}
 
 	// Y
 	if height <= innerBounds.Dy() {
 		this.scroll.Y = 0
-	} else if this.scroll.Y < 0 {
+	} else if this.scroll.Y > 0 {
 		this.scroll.Y = 0
-	} else if this.scroll.Y > height - innerBounds.Dy() {
-		this.scroll.Y = height - innerBounds.Dy()
+	} else if this.scroll.Y < innerBounds.Dy() - height {
+		this.scroll.Y = innerBounds.Dy() - height
 	}
 }