diff --git a/configs/voicemail.conf.sample b/configs/voicemail.conf.sample
index c58d733a0dca143b8674432d115514db04d0e58d..b67a6850577e9239fc2edabc3d4638c8d9ef58ac 100644
--- a/configs/voicemail.conf.sample
+++ b/configs/voicemail.conf.sample
@@ -188,6 +188,7 @@ sendvoicemail=yes	; Context to Send voicemail from [option 5 from the advanced m
 ; volgain=0.0		; Emails bearing the voicemail may arrive in a volume too
 			;     quiet to be heard.  This parameter allows you to specify how
 			;     much gain to add to the message when sending a voicemail.
+			;     NOTE: sox must be installed for this option to work.
 ; nextaftercmd=yes	; Skips to the next message after hitting 7 or 9 to delete/save current message.
 			;     [global option only at this time] 
 ; forcename=yes		; Forces a new user to record their name.  A new user is