QStringList can't handle single strings in QML

Given a QObject exposed to QML with a QStringList property, foo, one would expect the two following lines to give the same result
foo: "A"
foo: ["A"]
As list properties in QML do not require square brackets for lists of size one.

However, with QStringList only the second line works, the first line gives the following error message:

Invalid property assignment: unsupported type "QStringList"
foo: "A"

Failing project attached.