Given the following expression var x = MySingleton.MyEnumValue where MySingleton is a QML (composite) singleton and MyEnumValue comes from a QML declared enum, we had code in place up to (and including) 5.10 to attempt to optimize that expression to a enum constant at compile time. In 5.10 that optimization does not exist anymore. In <= 5.10 we would also skip the optimization under certain circumstances (too many statementes, etc.). The fallback that is in place for handling this at run-time tried to be smart by avoiding the QQmlContextWrapper::get lookup and return straight a reference to the singleton as QObject. That works for regular property lookups, but it fails when trying to look up something like an enum, that isn't a meta-object property. Change-Id: I1819b9d8ae06a3f595e067bf5b018c4065be76bb Reviewed-by: Lars Knoll <lars.knoll@qt.io>