diff --git a/src/mess/machine/psxcard.c b/src/mess/machine/psxcard.c
index 95f15125da5..342f4acb23e 100644
--- a/src/mess/machine/psxcard.c
+++ b/src/mess/machine/psxcard.c
@@ -50,6 +50,8 @@ void psxcard_device::device_start()
 	m_owner = dynamic_cast<psx_controller_port_device *>(owner());
 	m_ack_timer = machine().scheduler().timer_alloc(timer_expired_delegate(FUNC(psxcard_device::ack_timer), this));
 
+	m_ack = true;
+
 	// save state registrations
 /*  save_item(NAME(pkt));
     save_item(NAME(pkt_ptr));