diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
index e9f4043966ae..0798ac74d972 100644
--- a/drivers/iio/adc/ad7606_spi.c
+++ b/drivers/iio/adc/ad7606_spi.c
@@ -151,7 +151,7 @@ static int ad7606_spi_reg_write(struct ad7606_state *st,
 	struct spi_device *spi = to_spi_device(st->dev);
 
 	st->d16[0] = cpu_to_be16((st->bops->rd_wr_cmd(addr, 1) << 8) |
-				  (val & 0x1FF));
+				  (val & 0xFF));
 
 	return spi_write(spi, &st->d16[0], sizeof(st->d16[0]));
 }