diff --git a/scroll-animations-1/Overview.bs b/scroll-animations-1/Overview.bs
index 031790489658..83de29921958 100755
--- a/scroll-animations-1/Overview.bs
+++ b/scroll-animations-1/Overview.bs
@@ -1103,7 +1103,7 @@ interface CSSScrollTimelineRule : CSSRule {
 					fill: "forwards"
 				});
 			let timeline = new ScrollTimeline({
-				scrollSource: document.documentElement,
+				source: document.documentElement,
 				orientation: "vertical",
 			});
 			let animation = new Animation(effect, timeline);