--- a/dom/animation/test/mozilla/file_restyles.html
+++ b/dom/animation/test/mozilla/file_restyles.html
@@ -950,17 +950,17 @@ waitForAllPaints(() => {
          '!important rule begins running on the compositor even if the ' +
          '!important rule had been dropped before the target element was ' +
          'removed');
 
       await ensureElementRemoval(div);
     }
   );
 
-  // Tests that additive animations don't throttle at all.
+  // Tests that missing keyframes animations don't throttle at all.
   add_task(async function no_throttling_animations_out_of_view_element() {
     var div = addDiv(null, { style: 'transform: translateY(-400px);' });
     var animation =
       div.animate([{ visibility: 'visible' }], 100 * MS_PER_SEC);
 
     await animation.ready;
 
     const expectedRestyleCount = tweakExpectedRestyleCount(animation, 5);