diff --git a/src/emu/machine/6821pia.c b/src/emu/machine/6821pia.c
index a4aefd1d1d2..0ee12f91743 100644
--- a/src/emu/machine/6821pia.c
+++ b/src/emu/machine/6821pia.c
@@ -48,7 +48,9 @@ const device_type PIA6821 = &device_creator<pia6821_device>;
 //-------------------------------------------------
 
 pia6821_device::pia6821_device(const machine_config &mconfig, const char *tag, device_t *owner, UINT32 clock)
-	: device_t(mconfig, PIA6821, "6822 PIA", tag, owner, clock)
+	: device_t(mconfig, PIA6821, "6822 PIA", tag, owner, clock),
+	m_in_cb1(0),
+	m_ctl_b(0)
 {
 	memset(static_cast<pia6821_interface *>(this), 0, sizeof(pia6821_interface));
 }