QPSQL driver not working when using the same named bind several places in a prepared statement

QPSQL driver not working when using the same named bind several places in a prepared statement, i.e. doing the following

query.prepare("SELECT * FROM invoice WHERE nr = :nr AND nr2 = :nr");
query.bindValue(":nr", 1001);
query.exec();

results in QPSQL sending the following to the database

PREPARE qpsqlpstmt_a AS ( SELECT * FROM invoice WHERE nr = $1 AND nr2 = $2)
EXECUTE qpsqlpstmt_a (NULL, 1001)