diff --git a/dom/animation/AnimationPlayer.cpp b/dom/animation/AnimationPlayer.cpp
index 16c8598d2094..fd824c81d4d1 100644
--- a/dom/animation/AnimationPlayer.cpp
+++ b/dom/animation/AnimationPlayer.cpp
@@ -236,6 +236,15 @@ AnimationPlayer::MaybePostRestyle() const
                                   nsChangeHint_AllReflowHints);
 }
 
+void
+AnimationPlayer::PostUpdate()
+{
+  AnimationPlayerCollection* collection = GetCollection();
+  if (collection) {
+    collection->NotifyPlayerUpdated();
+  }
+}
+
 StickyTimeDuration
 AnimationPlayer::SourceContentEnd() const
 {
diff --git a/dom/animation/AnimationPlayer.h b/dom/animation/AnimationPlayer.h
index 4e8c13013424..9de1c1bbc639 100644
--- a/dom/animation/AnimationPlayer.h
+++ b/dom/animation/AnimationPlayer.h
@@ -128,6 +128,7 @@ public:
 protected:
   void FlushStyle() const;
   void MaybePostRestyle() const;
+  void PostUpdate();
   StickyTimeDuration SourceContentEnd() const;
 
   nsIDocument* GetRenderedDocument() const;