diff --git a/widget/xpwidgets/nsBaseWidget.cpp b/widget/xpwidgets/nsBaseWidget.cpp
index ad8b62752b5e..22f50b3d0624 100644
--- a/widget/xpwidgets/nsBaseWidget.cpp
+++ b/widget/xpwidgets/nsBaseWidget.cpp
@@ -118,8 +118,31 @@ nsBaseWidget::nsBaseWidget()
 #ifdef DEBUG
   debug_RegisterPrefCallbacks();
 #endif
+
+  mShutdownObserver = new WidgetShutdownObserver(this);
+  nsContentUtils::RegisterShutdownObserver(mShutdownObserver);
 }
 
+NS_IMPL_ISUPPORTS1(WidgetShutdownObserver, nsIObserver)
+
+NS_IMETHODIMP
+WidgetShutdownObserver::Observe(nsISupports *aSubject,
+                                const char *aTopic,
+                                const PRUnichar *aData)
+{
+  if (strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID) == 0) {
+    mWidget->Shutdown();
+    nsContentUtils::UnregisterShutdownObserver(this);
+  }
+ return NS_OK;
+}
+
+void
+nsBaseWidget::Shutdown()
+{
+  DestroyCompositor();
+  mShutdownObserver = nullptr;
+}
 
 static void DeferredDestroyCompositor(CompositorParent* aCompositorParent,
                               CompositorChild* aCompositorChild)
@@ -171,6 +194,10 @@ nsBaseWidget::~nsBaseWidget()
     mLayerManager = nullptr;
   }
 
+  if (mShutdownObserver) {
+    nsContentUtils::UnregisterShutdownObserver(mShutdownObserver);
+  }
+
   DestroyCompositor();
 
 #ifdef NOISY_WIDGET_LEAKS
@@ -893,6 +920,12 @@ void nsBaseWidget::CreateCompositor(int aWidth, int aHeight)
   // Recreating this is tricky, as we may still have an old and we need
   // to make sure it's properly destroyed by calling DestroyCompositor!
 
+  // If we've already received a shutdown notification, don't try
+  // create a new compositor.
+  if (!mShutdownObserver) {
+    return;
+  }
+
   mCompositorParent = NewCompositorParent(aWidth, aHeight);
   AsyncChannel *parentChannel = mCompositorParent->GetIPCChannel();
   LayerManager* lm = new ClientLayerManager(this);
diff --git a/widget/xpwidgets/nsBaseWidget.h b/widget/xpwidgets/nsBaseWidget.h
index 87ff5eedc752..d3efcb931b39 100644
--- a/widget/xpwidgets/nsBaseWidget.h
+++ b/widget/xpwidgets/nsBaseWidget.h
@@ -15,6 +15,7 @@
 #include "nsGUIEvent.h"
 #include "nsAutoPtr.h"
 #include "nsIRollupListener.h"
+#include "nsIObserver.h"
 #include <algorithm>
 class nsIContent;
 class nsAutoRollup;
@@ -38,6 +39,22 @@ namespace base {
 class Thread;
 }
 
+class nsBaseWidget;
+
+class WidgetShutdownObserver MOZ_FINAL : public nsIObserver
+{
+public:
+  WidgetShutdownObserver(nsBaseWidget* aWidget)
+    : mWidget(aWidget)
+  { }
+
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIOBSERVER
+
+private:
+  nsBaseWidget *mWidget;
+};
+
 /**
  * Common widget implementation used as base class for native
  * or crossplatform implementations of Widgets. 
@@ -254,6 +271,8 @@ public:
 
   static nsIRollupListener* GetActiveRollupListener();
 
+  void Shutdown();
+
 protected:
 
   virtual void            ResolveIconName(const nsAString &aIconName,
@@ -356,6 +375,7 @@ protected:
   nsRefPtr<LayerManager> mBasicLayerManager;
   nsRefPtr<CompositorChild> mCompositorChild;
   nsRefPtr<CompositorParent> mCompositorParent;
+  nsCOMPtr<WidgetShutdownObserver> mShutdownObserver;
   nscolor           mBackground;
   nscolor           mForeground;
   nsCursor          mCursor;