diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index d3e53a6d8331..5c62bfb0f3f5 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1569,7 +1569,8 @@ What:		/sys/bus/iio/devices/iio:deviceX/in_concentrationX_voc_raw
 KernelVersion:	4.3
 Contact:	linux-iio@vger.kernel.org
 Description:
-		Raw (unscaled no offset etc.) percentage reading of a substance.
+		Raw (unscaled no offset etc.) reading of a substance. Units
+		after application of scale and offset are percents.
 
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistance_raw
 What:		/sys/bus/iio/devices/iio:deviceX/in_resistanceX_raw