diff --git a/js/src/jsfriendapi.cpp b/js/src/jsfriendapi.cpp
index f792eafca54..f6fb42d0d38 100644
--- a/js/src/jsfriendapi.cpp
+++ b/js/src/jsfriendapi.cpp
@@ -412,6 +412,8 @@ js::AssertSameCompartment(JSObject *objA, JSObject *objB)
 JS_FRIEND_API(JSObject *)
 js::DefaultObjectForContextOrNull(JSContext *cx)
 {
+    if (cx->options().noDefaultCompartmentObject())
+        return nullptr;
     return cx->maybeDefaultCompartmentObject();
 }
 
diff --git a/js/xpconnect/src/XPCJSContextStack.cpp b/js/xpconnect/src/XPCJSContextStack.cpp
index 6aec91be18f..8429611b5b2 100644
--- a/js/xpconnect/src/XPCJSContextStack.cpp
+++ b/js/xpconnect/src/XPCJSContextStack.cpp
@@ -175,6 +175,7 @@ XPCJSContextStack::InitSafeJSContext()
     if (!mSafeJSContext)
         MOZ_CRASH();
     JSAutoRequest req(mSafeJSContext);
+    ContextOptionsRef(mSafeJSContext).setNoDefaultCompartmentObject(true);
 
     JS_SetErrorReporter(mSafeJSContext, xpc::SystemErrorReporter);
 
@@ -187,10 +188,6 @@ XPCJSContextStack::InitSafeJSContext()
         MOZ_CRASH();
     JS_AddNamedObjectRoot(mSafeJSContext, &mSafeJSContextGlobal, "SafeJSContext global");
 
-    // Make sure the context is associated with a proper compartment
-    // and not the default compartment.
-    js::SetDefaultObjectForContext(mSafeJSContext, mSafeJSContextGlobal);
-
     // Note: make sure to set the private before calling
     // InitClasses
     nsRefPtr<SandboxPrivate> sp = new SandboxPrivate(principal, mSafeJSContextGlobal);
diff --git a/js/xpconnect/src/nsCxPusher.cpp b/js/xpconnect/src/nsCxPusher.cpp
index 15388993141..202115104b1 100644
--- a/js/xpconnect/src/nsCxPusher.cpp
+++ b/js/xpconnect/src/nsCxPusher.cpp
@@ -228,6 +228,7 @@ ThreadsafeAutoJSContext::operator JSContext*() const
 
 AutoSafeJSContext::AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
   : AutoJSContext(true MOZ_GUARD_OBJECT_NOTIFIER_PARAM_TO_PARENT)
+  , mAc(mCx, XPCJSRuntime::Get()->GetJSContextStack()->GetSafeJSContextGlobal())
 {
 }
 
diff --git a/js/xpconnect/src/nsCxPusher.h b/js/xpconnect/src/nsCxPusher.h
index d6848050d2e..7b86e8bac3f 100644
--- a/js/xpconnect/src/nsCxPusher.h
+++ b/js/xpconnect/src/nsCxPusher.h
@@ -100,7 +100,6 @@ public:
 protected:
   AutoJSContext(bool aSafe MOZ_GUARD_OBJECT_NOTIFIER_PARAM);
 
-private:
   // We need this Init() method because we can't use delegating constructor for
   // the moment. It is a C++11 feature and we do not require C++11 to be
   // supported to be able to compile Gecko.
@@ -134,6 +133,8 @@ private:
 class MOZ_STACK_CLASS AutoSafeJSContext : public AutoJSContext {
 public:
   AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
+private:
+  JSAutoCompartment mAc;
 };
 
 /**