--- a/dom/animation/KeyframeEffect.cpp
+++ b/dom/animation/KeyframeEffect.cpp
@@ -184,17 +184,17 @@ KeyframeEffectReadOnly::NotifyAnimationT
   // Bug 1216843: When we implement iteration composite modes, we need to
   // also detect if the current iteration has changed.
   if (mAnimation && GetComputedTiming().mProgress != mProgressOnLastCompose) {
     EffectCompositor::RestyleType restyleType =
       CanThrottle() ?
       EffectCompositor::RestyleType::Throttled :
       EffectCompositor::RestyleType::Standard;
     nsPresContext* presContext = GetPresContext();
-    if (presContext) {
+    if (presContext && mTarget) {
       presContext->EffectCompositor()->
         RequestRestyle(mTarget, mPseudoType, restyleType,
                        mAnimation->CascadeLevel());
     }
 
     // If we're not relevant, we will have been removed from the EffectSet.
     // As a result, when the restyle we requested above is fulfilled, our
     // ComposeStyle will not get called and mProgressOnLastCompose will not
@@ -558,25 +558,25 @@ KeyframeEffectReadOnly::UpdateProperties
       runningOnCompositorProperties.HasProperty(property.mProperty);
   }
 
   if (mTarget) {
     EffectSet* effectSet = EffectSet::GetEffectSet(mTarget, mPseudoType);
     if (effectSet) {
       effectSet->MarkCascadeNeedsUpdate();
     }
-  }
 
-  if (mAnimation) {
-    nsPresContext* presContext = GetPresContext();
-    if (presContext) {
-      presContext->EffectCompositor()->
-        RequestRestyle(mTarget, mPseudoType,
-                       EffectCompositor::RestyleType::Layer,
-                       mAnimation->CascadeLevel());
+    if (mAnimation) {
+      nsPresContext* presContext = GetPresContext();
+      if (presContext) {
+        presContext->EffectCompositor()->
+          RequestRestyle(mTarget, mPseudoType,
+                         EffectCompositor::RestyleType::Layer,
+                         mAnimation->CascadeLevel());
+      }
     }
   }
 }
 
 void
 KeyframeEffectReadOnly::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
                                      nsCSSPropertySet& aSetProperties)
 {
@@ -1354,27 +1354,28 @@ KeyframeEffect::Constructor(
 {
   return ConstructKeyframeEffect<KeyframeEffect>(aGlobal, aTarget, aFrames,
                                                  aOptions, aRv);
 }
 
 void KeyframeEffect::NotifySpecifiedTimingUpdated()
 {
   // Use the same document for a pseudo element and its parent element.
-  nsAutoAnimationMutationBatch mb(mTarget->OwnerDoc());
+  // Use nullptr if we don't have mTarget, so disable the mutation batch.
+  nsAutoAnimationMutationBatch mb(mTarget ? mTarget->OwnerDoc() : nullptr);
 
   if (mAnimation) {
     mAnimation->NotifyEffectTimingUpdated();
 
     if (mAnimation->IsRelevant()) {
       nsNodeUtils::AnimationChanged(mAnimation);
     }
 
     nsPresContext* presContext = GetPresContext();
-    if (presContext) {
+    if (presContext && mTarget) {
       presContext->EffectCompositor()->
         RequestRestyle(mTarget, mPseudoType,
                        EffectCompositor::RestyleType::Layer,
                        mAnimation->CascadeLevel());
     }
   }
 }