diff --git a/doc/media-api.txt b/doc/media-api.txt
index 7a593c3..4446439 100644
--- a/doc/media-api.txt
+++ b/doc/media-api.txt
@@ -341,3 +341,11 @@ Properties	object Device [readonly]
 			Optional. Indicates where is the transport being routed
 
 			Possible Values: "HCI" or "PCM"
+
+		uint16 Volume [readwrite]
+
+			Optional. Indicates volume level of the transport,
+			this property is only writeable when the transport was
+			acquired by the sender.
+
+			Possible Values: 0-127