OCI: When binding a QByteArray to a CLOB field it does not get written correctly

#include <QtCore>
#include <QtSql>

int main(int argc, char **argv)
{
    QCoreApplication a(argc, argv);
    QVariant var;
    {
        QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
        db.setDatabaseName(":memory:");
        db.open();
        QSqlQuery q;
        q.exec("CREATE TABLE TEST(id int, myText text)");
        q.exec("INSERT INTO TEST(1, 'ABCD')");
        q.exec("SELECT * from TEST");
        q.next();
        var = q.value(1);
    }
    {
        QSqlDatabase db = QSqlDatabase::addDatabase("QOCI");
        db.setDatabaseName("ocidb");
        db.setUserName("ociuser");
        db.setPassword("ocipass");
        db.open();
        QSqlQuery q;
        q.exec("CREATE TABLE TEST(id number(10), myText clob)");
        q.prepare("INSERT INTO TEST(1, :txt)");
        q.bindValue(":txt", var);
        q.exec();
        QSqlQuery selectQ;
        selectQ.exec("SELECT * from TEST");
        q.next();
        qDebug() << q.value(1);
    }
    return 0;
}