diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index b1258a796d6b2fd15bba5eb5b4f1af78211e8dd0..21e463f9f653ff7b7c5687a439403a910a050883 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -12635,7 +12635,7 @@ static int transmit_invite(struct sip_pvt *p, int sipmethod, int sdp, int init,
 		/* If init=1, we should not generate a new branch. If it's 0, we need a new branch. */
 		reqprep(&req, p, sipmethod, 0, init ? 0 : 1);
 	}
-		
+
 	if (p->options && p->options->auth) {
 		add_header(&req, p->options->authheader, p->options->auth);
 	}
@@ -20552,6 +20552,10 @@ static void check_pendings(struct sip_pvt *p)
 		if (p->invitestate == INV_PROCEEDING || p->invitestate == INV_EARLY_MEDIA) {
 			p->invitestate = INV_CANCELLED;
 			transmit_request(p, SIP_CANCEL, p->lastinvite, XMIT_RELIABLE, FALSE);
+			/* If the cancel occurred on an initial invite, cancel the pending BYE */
+			if (!ast_test_flag(&p->flags[1], SIP_PAGE2_DIALOG_ESTABLISHED)) {
+				ast_clear_flag(&p->flags[0], SIP_PENDINGBYE);
+			}
 			/* Actually don't destroy us yet, wait for the 487 on our original
 			   INVITE, but do set an autodestruct just in case we never get it. */
 		} else {
@@ -20565,8 +20569,8 @@ static void check_pendings(struct sip_pvt *p)
 			}
 			/* Perhaps there is an SD change INVITE outstanding */
 			transmit_request_with_auth(p, SIP_BYE, 0, XMIT_RELIABLE, TRUE);
+			ast_clear_flag(&p->flags[0], SIP_PENDINGBYE);
 		}
-		ast_clear_flag(&p->flags[0], SIP_PENDINGBYE);
 		sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
 	} else if (ast_test_flag(&p->flags[0], SIP_NEEDREINVITE)) {
 		/* if we can't REINVITE, hold it for later */
@@ -20728,7 +20732,7 @@ static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest
 	int outgoing = ast_test_flag(&p->flags[0], SIP_OUTGOING);
 	int res = 0;
 	int xmitres = 0;
-	int reinvite = (p->owner && ast_channel_state(p->owner) == AST_STATE_UP);
+	int reinvite = ast_test_flag(&p->flags[1], SIP_PAGE2_DIALOG_ESTABLISHED);
 	char *p_hdrval;
 	int rtn;
 	struct ast_party_connected_line connected;
@@ -20934,10 +20938,11 @@ static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest
 		p->authtries = 0;
 		if (find_sdp(req)) {
 			if ((res = process_sdp(p, req, SDP_T38_ACCEPT)) && !req->ignore)
-				if (!reinvite)
+				if (!reinvite) {
 					/* This 200 OK's SDP is not acceptable, so we need to ack, then hangup */
 					/* For re-invites, we try to recover */
 					ast_set_flag(&p->flags[0], SIP_PENDINGBYE);
+				}
 			ast_rtp_instance_activate(p->rtp);
 		}
 
@@ -20984,7 +20989,6 @@ static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest
 			if (!reinvite) {
 				build_route(p, req, 1, resp);
 			}
-
 			if(set_address_from_contact(p)) {
 				/* Bad contact - we don't know how to reach this device */
 				/* We need to ACK, but then send a bye */
@@ -21138,6 +21142,7 @@ static void handle_response_invite(struct sip_pvt *p, int resp, const char *rest
 			update_call_counter(p, DEC_CALL_LIMIT);
 			append_history(p, "Hangup", "Got 487 on CANCEL request from us on call without owner. Killing this dialog.");
 		}
+		check_pendings(p);
 		sip_scheddestroy(p, DEFAULT_TRANS_TIMEOUT);
 		break;
 	case 415: /* Unsupported media type */
@@ -21834,8 +21839,9 @@ static void handle_response(struct sip_pvt *p, int resp, const char *rest, struc
 	}
 
 	/* If this is a NOTIFY for a subscription clear the flag that indicates that we have a NOTIFY pending */
-	if (!p->owner && sipmethod == SIP_NOTIFY && p->pendinginvite)
+	if (!p->owner && sipmethod == SIP_NOTIFY && p->pendinginvite) {
 		p->pendinginvite = 0;
+	}
 
 	/* Get their tag if we haven't already */
 	if (ast_strlen_zero(p->theirtag) || (resp >= 200)) {