--- a/widget/cocoa/nsNativeThemeCocoa.mm
+++ b/widget/cocoa/nsNativeThemeCocoa.mm
@@ -2378,17 +2378,22 @@ nsNativeThemeCocoa::DrawWidgetBackground
           CheckBooleanAttr(GetParentScrollbarFrame(aFrame), nsGkAtoms::hover)) {
         BOOL isHorizontal = (aWidgetType == NS_THEME_SCROLLBAR_TRACK_HORIZONTAL);
         if (!nsCocoaFeatures::OnMountainLionOrLater()) {
           // On OSX 10.7, scrollbars don't grow when hovered. The adjustments
           // below were obtained by trial and error.
           if (isHorizontal) {
             macRect.origin.y += 2.0;
           } else {
-            macRect.origin.x += 3.0;
+            if (aFrame->StyleVisibility()->mDirection !=
+                  NS_STYLE_DIRECTION_RTL) {
+              macRect.origin.x += 3.0;
+            } else {
+              macRect.origin.x -= 1.0;
+            }
           }
         }
         const BOOL isOnTopOfDarkBackground = IsDarkBackground(aFrame);
         CUIDraw([NSWindow coreUIRenderer], macRect, cgContext,
                 (CFDictionaryRef)[NSDictionary dictionaryWithObjectsAndKeys:
                   @"kCUIWidgetOverlayScrollBar", @"widget",
                   @"regular", @"size",
                   (isHorizontal ? @"kCUIOrientHorizontal" : @"kCUIOrientVertical"), @"kCUIOrientationKey",