diff --git a/widget/cocoa/nsNativeThemeCocoa.mm b/widget/cocoa/nsNativeThemeCocoa.mm
index 3c86954424..597c25a486 100644
--- a/widget/cocoa/nsNativeThemeCocoa.mm
+++ b/widget/cocoa/nsNativeThemeCocoa.mm
@@ -2778,7 +2778,8 @@ nsNativeThemeCocoa::DrawWidgetBackground(nsRenderingContext* aContext,
       NSMutableDictionary* options = [NSMutableDictionary dictionaryWithObjectsAndKeys:
         (isOverlay ? @"kCUIWidgetOverlayScrollBar" : @"scrollbar"), @"widget",
         (isSmall ? @"small" : @"regular"), @"size",
-        (isHorizontal ? @"kCUIOrientHorizontal" : @"kCUIOrientVertical"), @"kCUIOrientationKey",
+        (isOverlay && isOnTopOfDarkBackground ? @"kCUIVariantWhite" : @""),
+          @"kCUIVariantKey",
         (isOnTopOfDarkBackground ? @"kCUIVariantWhite" : @""), @"kCUIVariantKey",
         [NSNumber numberWithBool:YES], @"indiconly",
         [NSNumber numberWithBool:YES], @"kCUIThumbProportionKey",