diff --git a/src/call.h b/src/call.h
index 1c35a9d..fe47e15 100644
--- a/src/call.h
+++ b/src/call.h
@@ -71,6 +71,11 @@ enum sip_cc_state {
 	SIP_CC_CONNECTED,
 };
 
+enum sip_dir {
+	SIP_DIR_MO,
+	SIP_DIR_MT,
+};
+
 struct sip_call_leg {
 	/* base class */
 	struct call_leg base;
@@ -81,6 +86,7 @@ struct sip_call_leg {
 	/* per instance members */
 	struct nua_handle_s *nua_handle;
 	enum sip_cc_state state;
+	enum sip_dir dir;
 	const char *wanted_codec;
 };
 
diff --git a/src/sip.c b/src/sip.c
index b5a9d5c..6956cca 100644
--- a/src/sip.c
+++ b/src/sip.c
@@ -251,6 +251,7 @@ static int send_invite(struct sip_agent *agent, struct sip_call_leg *leg,
 				leg->wanted_codec);
 
 	leg->state = SIP_CC_INITIAL;
+	leg->dir = SIP_DIR_MT;
 	nua_invite(leg->nua_handle,
 			SIPTAG_FROM_STR(from),
 			SIPTAG_TO_STR(to),