diff --git a/mozilla/xpcom/threads/nsEventQueue.cpp b/mozilla/xpcom/threads/nsEventQueue.cpp
index 04a945f2495..f7608beb048 100644
--- a/mozilla/xpcom/threads/nsEventQueue.cpp
+++ b/mozilla/xpcom/threads/nsEventQueue.cpp
@@ -135,7 +135,9 @@ nsEventQueueImpl::~nsEventQueueImpl()
 #endif
 
   if (mEventQueue) {
-    NotifyObservers(gDestroyedNotification);
+    // Perhaps CheckForDeactivation wasn't called...
+    if (mCouldHaveEvents)
+      NotifyObservers(gDestroyedNotification);
     PL_DestroyEventQueue(mEventQueue);
   }
 }
@@ -236,6 +238,19 @@ nsEventQueueImpl::NotifyObservers(const char *aTopic)
   }
 }
 
+void
+nsEventQueueImpl::CheckForDeactivation()
+{
+  if (mCouldHaveEvents && !mAcceptingEvents && !PL_EventAvailable(mEventQueue)) {
+    if (PL_IsQueueOnCurrentThread(mEventQueue)) {
+      mCouldHaveEvents = PR_FALSE;
+      NotifyObservers(gDestroyedNotification);
+      NS_RELEASE_THIS(); // balance ADDREF from the constructor
+    } else
+      NS_ERROR("CheckForDeactivation called from wrong thread!");
+  }
+}
+
 
 NS_IMETHODIMP
 nsEventQueueImpl::InitEvent(PLEvent* aEvent,
diff --git a/mozilla/xpcom/threads/nsEventQueue.h b/mozilla/xpcom/threads/nsEventQueue.h
index 51f33e478e4..7660e331a8b 100644
--- a/mozilla/xpcom/threads/nsEventQueue.h
+++ b/mozilla/xpcom/threads/nsEventQueue.h
@@ -75,15 +75,5 @@ private:
   nsPIEventQueueChain *mYoungerQueue; // but elder can't hold on to younger
 
   void NotifyObservers(const char *aTopic);
-
-  void CheckForDeactivation() {
-    if (mCouldHaveEvents && !mAcceptingEvents && !PL_EventAvailable(mEventQueue)) {
-      if (PL_IsQueueOnCurrentThread(mEventQueue)) {
-        mCouldHaveEvents = PR_FALSE;
-        NS_RELEASE_THIS(); // balance ADDREF from the constructor
-      } else
-        NS_ERROR("CheckForDeactivation called from wrong thread!");
-    }
-  }
+  void CheckForDeactivation();
 };
-