diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index ac46b9220c7bdae6021f7fa428fc42e0ce850ad7..61f25dbe010d0611f2d955c7a8719337620c1a9f 100755
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -3917,6 +3917,8 @@ static int transmit_state_notify(struct sip_pvt *p, int state, int full)
 		}
 		mto = c;
 
+		add_header(&req, "Event", "presence");
+		add_header(&req, "Subscription-State", "active");
 		add_header(&req, "Content-Type", "application/xpidf+xml");
 
 		if ((state==AST_EXTENSION_UNAVAILABLE) || (state==AST_EXTENSION_BUSY))