diff --git a/drivers/staging/iio/dac/ad5686.c b/drivers/staging/iio/dac/ad5686.c
index 1d50dd1..48389e1 100644
--- a/drivers/staging/iio/dac/ad5686.c
+++ b/drivers/staging/iio/dac/ad5686.c
@@ -327,7 +327,7 @@
 
 	switch (mask) {
 	case 0:
-		if (val > (1 << chan->scan_type.realbits))
+		if (val > (1 << chan->scan_type.realbits) || val < 0)
 			return -EINVAL;
 
 		mutex_lock(&indio_dev->mlock);