diff --git a/src/emu/sound/namco.c b/src/emu/sound/namco.c
index 9ce4728e691..fb332b655fe 100644
--- a/src/emu/sound/namco.c
+++ b/src/emu/sound/namco.c
@@ -398,6 +398,10 @@ static DEVICE_START( namco )
 
 	/* register with the save state system */
 	state_save_register_device_item_pointer(device, 0, chip->soundregs, 0x400);
+
+	if (device->region() == NULL)
+		state_save_register_device_item_pointer(device, 0, chip->wavedata, 0x400);
+
 	state_save_register_device_item(device, 0, chip->num_voices);
 	state_save_register_device_item(device, 0, chip->sound_enable);
 	state_save_register_device_item_pointer(device, 0, chip->waveform[0],