diff --git a/dom/bindings/DOMJSProxyHandler.cpp b/dom/bindings/DOMJSProxyHandler.cpp
index a21ac28a1b..c0e0662601 100644
--- a/dom/bindings/DOMJSProxyHandler.cpp
+++ b/dom/bindings/DOMJSProxyHandler.cpp
@@ -75,17 +75,9 @@ DOMProxyHandler::ClearExternalRefsForWrapperRelease(JSObject* obj)
 {
   MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
   JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
-  if (v.isUndefined()) {
-    // No expando.
-    return;
-  }
-
-  // See EnsureExpandoObject for the work we're trying to undo here.
-
-  if (v.isObject()) {
-    // Drop us from the DOM expando hashtable.  Don't worry about clearing our
-    // slot reference to the expando; we're about to die anyway.
-    xpc::ObjectScope(obj)->RemoveDOMExpandoObject(obj);
+  if (v.isUndefined() || v.isObject()) {
+    // No expando, or an expando that we reference from our slot anyway, so
+    // don't have to clear state for.
     return;
   }
 
@@ -108,7 +100,6 @@ DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
 
   if (v.isObject()) {
     js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, UndefinedValue());
-    xpc::ObjectScope(obj)->RemoveDOMExpandoObject(obj);
   } else {
     js::ExpandoAndGeneration* expandoAndGeneration =
       static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
@@ -168,19 +159,14 @@ DOMProxyHandler::EnsureExpandoObject(JSContext* cx, JS::Handle<JSObject*> obj)
   if (!cache) {
     return expando;
   }
+  cache->PreserveWrapper(native);
   
   if (expandoAndGeneration) {
-    cache->PreserveWrapper(native);
     expandoAndGeneration->expando.setObject(*expando);
 
     return expando;
   }
 
-  if (!xpc::ObjectScope(obj)->RegisterDOMExpandoObject(obj)) {
-    return nullptr;
-  }
-
-  cache->SetPreservingWrapper(true);
   js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, ObjectValue(*expando));
 
   return expando;