--- a/dom/animation/KeyframeEffect.cpp
+++ b/dom/animation/KeyframeEffect.cpp
@@ -1413,25 +1413,35 @@ KeyframeEffect::SetTarget(const Nullable
   }
 
   if (mTarget) {
     UnregisterTarget();
     ResetIsRunningOnCompositor();
     ResetWinsInCascade();
 
     RequestRestyle(EffectCompositor::RestyleType::Layer);
+
+    nsAutoAnimationMutationBatch mb(mTarget->mElement->OwnerDoc());
+    if (mAnimation) {
+      nsNodeUtils::AnimationRemoved(mAnimation);
+    }
   }
 
   mTarget = newTarget;
 
   if (mTarget) {
     UpdateTargetRegistration();
     MaybeUpdateProperties();
 
     RequestRestyle(EffectCompositor::RestyleType::Layer);
+
+    nsAutoAnimationMutationBatch mb(mTarget->mElement->OwnerDoc());
+    if (mAnimation) {
+      nsNodeUtils::AnimationAdded(mAnimation);
+    }
   }
 }
 
 KeyframeEffect::~KeyframeEffect()
 {
   // mTiming is cycle collected, so we have to do null check first even though
   // mTiming shouldn't be null during the lifetime of KeyframeEffect.
   if (mTiming) {