diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 28b91a6c3789..b5a19a0863fb 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -772,6 +772,8 @@ void labpc_common_detach(struct comedi_device *dev)
 {
 	struct comedi_subdevice *s;
 
+	if (!thisboard)
+		return;
 	if (dev->subdevices) {
 		s = &dev->subdevices[2];
 		subdev_8255_cleanup(dev, s);