Removing QStateMachine with circural references between states fails

from PySide.QtCore import *

class TestMachine(QStateMachine):
    s = Signal()
    def __init__(self):
        super(TestMachine, self).__init__()
        self.state1 = QState(self)
        self.state2 = QState(self)
        self.state1.addTransition(self.state2)
        self.state2.addTransition(self.state1)
test = TestMachine()
print "Removing TestMachine"
test = None
print "Done"

Removing TestMachine