diff --git a/features/web-animations.yml b/features/web-animations.yml
index b0ed9c2c55c..235dfc45345 100644
--- a/features/web-animations.yml
+++ b/features/web-animations.yml
@@ -46,6 +46,7 @@ compat_features:
   - api.Animation.timeline
   - api.AnimationTimeline
   - api.AnimationTimeline.currentTime
+  - api.AnimationTimeline.duration
   - api.Document.timeline
   - api.DocumentTimeline
   - api.DocumentTimeline.DocumentTimeline
diff --git a/features/web-animations.yml.dist b/features/web-animations.yml.dist
index e0beb1924c3..e23681a619a 100644
--- a/features/web-animations.yml.dist
+++ b/features/web-animations.yml.dist
@@ -240,6 +240,7 @@ compat_features:
   #   chrome: "115"
   #   chrome_android: "115"
   #   edge: "115"
+  - api.AnimationTimeline.duration
   - api.Element.animate.options_rangeEnd_parameter
   - api.Element.animate.options_rangeStart_parameter