diff --git a/dom/animation/AnimationPlayer.cpp b/dom/animation/AnimationPlayer.cpp
index 0d7686486dab..c2246a3a55ee 100644
--- a/dom/animation/AnimationPlayer.cpp
+++ b/dom/animation/AnimationPlayer.cpp
@@ -349,7 +349,9 @@ AnimationPlayer::Cancel()
 bool
 AnimationPlayer::IsRunning() const
 {
-  if (IsPaused() || !GetSource() || GetSource()->IsFinishedTransition()) {
+  if (IsPausedOrPausing() ||
+      !GetSource() ||
+      GetSource()->IsFinishedTransition()) {
     return false;
   }
 
diff --git a/dom/animation/AnimationPlayer.h b/dom/animation/AnimationPlayer.h
index 3b07ea9078c4..255f406ed136 100644
--- a/dom/animation/AnimationPlayer.h
+++ b/dom/animation/AnimationPlayer.h
@@ -191,17 +191,24 @@ public:
 
   void Cancel();
 
-  const nsString& Name() const {
+  const nsString& Name() const
+  {
     return mSource ? mSource->Name() : EmptyString();
   }
 
-  bool IsPaused() const { return PlayState() == AnimationPlayState::Paused; }
+  bool IsPausedOrPausing() const
+  {
+    return PlayState() == AnimationPlayState::Paused ||
+           mPendingState == PendingState::PausePending;
+  }
   bool IsRunning() const;
 
-  bool HasCurrentSource() const {
+  bool HasCurrentSource() const
+  {
     return GetSource() && GetSource()->IsCurrent();
   }
-  bool HasInEffectSource() const {
+  bool HasInEffectSource() const
+  {
     return GetSource() && GetSource()->IsInEffect();
   }
 
diff --git a/layout/style/nsAnimationManager.cpp b/layout/style/nsAnimationManager.cpp
index fc14eece201b..58f4ba881886 100644
--- a/layout/style/nsAnimationManager.cpp
+++ b/layout/style/nsAnimationManager.cpp
@@ -348,11 +348,12 @@ nsAnimationManager::CheckAnimationRule(nsStyleContext* aStyleContext,
         // (We should check newPlayer->IsStylePaused() but that requires
         //  downcasting to CSSAnimationPlayer and we happen to know that
         //  newPlayer will only ever be paused by calling PauseFromStyle
-        //  making IsPaused synonymous in this case.)
-        if (!oldPlayer->IsStylePaused() && newPlayer->IsPaused()) {
+        //  making IsPausedOrPausing synonymous in this case.)
+        if (!oldPlayer->IsStylePaused() && newPlayer->IsPausedOrPausing()) {
           oldPlayer->PauseFromStyle();
           animationChanged = true;
-        } else if (oldPlayer->IsStylePaused() && !newPlayer->IsPaused()) {
+        } else if (oldPlayer->IsStylePaused() &&
+                   !newPlayer->IsPausedOrPausing()) {
           oldPlayer->PlayFromStyle();
           animationChanged = true;
         }