Storing QJSValue references while using QJSEngine::evaluate() results in garbage collection issue

There is QObject exposed to javascript allowing to load javascript from file, evaluate it and reference it in the calling js code (method require()). Also it stores QJSValue for the future usage (e.g. return it if the same name will be requested). It results in maybe missed reference (garbage collector is trying to gather it while reference still exists). See attachment (needs cmake 2.8.8+ but can be modified to use qmake easily I guess )