--- a/gfx/layers/apz/src/AsyncPanZoomController.cpp
+++ b/gfx/layers/apz/src/AsyncPanZoomController.cpp
@@ -4179,16 +4179,19 @@ void AsyncPanZoomController::NotifyLayer
       // Since the scroll offset has changed, we need to recompute the
       // displayport margins and send them to layout. Otherwise there might be
       // scenarios where for example we scroll from the top of a page (where the
       // top displayport margin is zero) to the bottom of a page, which will
       // result in a displayport that doesn't extend upwards at all.
       // Note that even if the CancelAnimation call above requested a repaint
       // this is fine because we already have repaint request deduplication.
       needContentRepaint = true;
+      // Since the main-thread scroll offset changed we should trigger a
+      // recomposite to make sure it becomes user-visible.
+      ScheduleComposite();
     } else if (scrollableRectChanged) {
       // Even if we didn't accept a new scroll offset from content, the
       // scrollable rect may have changed in a way that makes our local
       // scroll offset out of bounds, so re-clamp it.
       mFrameMetrics.ClampAndSetScrollOffset(mFrameMetrics.GetScrollOffset());
     }
   }