diff --git a/dom/base/nsCCUncollectableMarker.cpp b/dom/base/nsCCUncollectableMarker.cpp
index 7936d07b051d..8e54b38c1fd0 100644
--- a/dom/base/nsCCUncollectableMarker.cpp
+++ b/dom/base/nsCCUncollectableMarker.cpp
@@ -508,7 +508,7 @@ mozilla::dom::TraceBlackJS(JSTracer* aTrc, uint32_t aGCNumber, bool aIsShutdownG
   if (windowsById) {
     for (auto iter = windowsById->Iter(); !iter.Done(); iter.Next()) {
       nsGlobalWindow* window = iter.Data();
-      if (!window->IsCleanedUp() && window->IsOuterWindow()) {
+      if (window->GetDocShell() && window->IsOuterWindow()) {
         window->TraceGlobalJSObject(aTrc);
         EventListenerManager* elm = window->GetExistingListenerManager();
         if (elm) {
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index 9e112f6543cc..e8037bf920ef 100644
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -668,12 +668,6 @@ public:
             mCleanedUp);
   }
 
-  bool
-  IsCleanedUp() const
-  {
-    return mCleanedUp;
-  }
-
   bool
   HadOriginalOpener() const
   {