diff --git a/doc/modem-api.txt b/doc/modem-api.txt
index 1c4e440f..9fd23ba6 100644
--- a/doc/modem-api.txt
+++ b/doc/modem-api.txt
@@ -167,4 +167,4 @@ Properties	boolean Powered [readwrite]
 			not give any hints on which Interfaces will be
 			supported by this modem.
 
-			Possible values are "hfp", "sap" and "hardware".
+			Possible values are "test", "hfp", "sap" and "hardware".