diff --git a/drivers/staging/comedi/drivers/amplc_dio200.h b/drivers/staging/comedi/drivers/amplc_dio200.h
index f8d4d6fbf418..e51261b006e1 100644
--- a/drivers/staging/comedi/drivers/amplc_dio200.h
+++ b/drivers/staging/comedi/drivers/amplc_dio200.h
@@ -49,7 +49,6 @@ struct dio200_board {
 	struct dio200_layout layout;
 	unsigned char mainbar;
 	unsigned char mainshift;
-	unsigned int mainsize;
 };
 
 int amplc_dio200_common_attach(struct comedi_device *dev, unsigned int irq,