diff -Nur a/res/res_pjsip_nat.c b/res/res_pjsip_nat.c
--- a/res/res_pjsip_nat.c	2023-04-03 17:47:51.000000000 +0200
+++ b/res/res_pjsip_nat.c	2023-04-06 11:39:14.706883902 +0200
@@ -444,10 +444,19 @@
 			pjsip_method_cmp(&cseq->method, &pjsip_register_method)) {
 			/* We can only rewrite the URI when one is present */
 			if (uri || (uri = nat_get_contact_sip_uri(tdata))) {
-				pj_strdup2(tdata->pool, &uri->host, ast_sockaddr_stringify_host(&transport_state->external_signaling_address));
-				if (transport->external_signaling_port) {
-					uri->port = transport->external_signaling_port;
-					ast_debug(4, "Re-wrote Contact URI port to %d\n", uri->port);
+				/* Don't update Contact header if 302 Response to INVITE
+				 * Request
+				 */
+				if ( !(tdata->msg->type == PJSIP_RESPONSE_MSG &&
+					!pjsip_method_cmp(&cseq->method, &pjsip_invite_method) &&
+					tdata->msg->line.status.code == PJSIP_SC_MOVED_TEMPORARILY)) {
+					pj_strdup2(tdata->pool, &uri->host, ast_sockaddr_stringify_host(&transport_state->external_signaling_address));
+					if (transport->external_signaling_port) {
+						uri->port = transport->external_signaling_port;
+						ast_debug(4, "Re-wrote Contact URI port to %d\n", uri->port);
+					}
+				} else {
+					ast_debug(4, "Redirect (302), no NAT handling\n");
 				}
 			}
 		}