diff --git a/drivers/staging/comedi/drivers/amplc_pc236.c b/drivers/staging/comedi/drivers/amplc_pc236.c
index 36768b2b30ae..4e4f3c15df87 100644
--- a/drivers/staging/comedi/drivers/amplc_pc236.c
+++ b/drivers/staging/comedi/drivers/amplc_pc236.c
@@ -574,6 +574,8 @@ static void pc236_detach(struct comedi_device *dev)
 {
 	const struct pc236_board *thisboard = comedi_board(dev);
 
+	if (!thisboard)
+		return;
 	if (dev->iobase)
 		pc236_intr_disable(dev);
 	if (dev->irq)