diff --git a/js/src/jswrapper.cpp b/js/src/jswrapper.cpp
index 3a0af41c2dee..808d8cde5ba4 100644
--- a/js/src/jswrapper.cpp
+++ b/js/src/jswrapper.cpp
@@ -295,6 +295,7 @@ JSObject *
 JSWrapper::New(JSContext *cx, JSObject *obj, JSObject *proto, JSObject *parent,
                JSWrapper *handler)
 {
+    JS_ASSERT(parent);
     return NewProxyObject(cx, handler, ObjectValue(*obj), proto, parent,
                           obj->isCallable() ? obj : NULL, NULL);
 }
@@ -345,6 +346,7 @@ AutoCompartment::enter()
 
         context->compartment = destination;
         JSObject *scopeChain = target->getGlobal();
+        JS_ASSERT(scopeChain->isNative());
         frame.construct();
         if (!context->stack().pushDummyFrame(context, *scopeChain, &frame.ref())) {
             frame.destroy();
diff --git a/js/src/xpconnect/wrappers/WrapperFactory.cpp b/js/src/xpconnect/wrappers/WrapperFactory.cpp
index 639c7cdc78d2..100fcb4249b8 100644
--- a/js/src/xpconnect/wrappers/WrapperFactory.cpp
+++ b/js/src/xpconnect/wrappers/WrapperFactory.cpp
@@ -71,7 +71,7 @@ DoubleWrap(JSContext *cx, JSObject *obj, uintN flags)
 {
     if (flags & WrapperFactory::WAIVE_XRAY_WRAPPER_FLAG) {
         js::SwitchToCompartment sc(cx, obj->compartment());
-        return JSWrapper::New(cx, obj, NULL, obj->getParent(),
+        return JSWrapper::New(cx, obj, NULL, obj->getGlobal(),
                               &WaiveXrayWrapperWrapper);
     }
     return obj;
@@ -323,7 +323,7 @@ WrapperFactory::WaiveXrayAndWrap(JSContext *cx, jsval *vp)
 
     {
         js::SwitchToCompartment sc(cx, obj->compartment());
-        obj = JSWrapper::New(cx, obj, NULL, obj->getParent(), &WaiveXrayWrapperWrapper);
+        obj = JSWrapper::New(cx, obj, NULL, obj->getGlobal(), &WaiveXrayWrapperWrapper);
         if (!obj)
             return false;
     }