diff --git a/res/res_pjsip/pjsip_resolver.c b/res/res_pjsip/pjsip_resolver.c
index 4d4d36e27508736bf17a32ebfec6dac6cb11de39..5a902466e3fd1e25bf39e9613353fe5b6a7a4eaa 100644
--- a/res/res_pjsip/pjsip_resolver.c
+++ b/res/res_pjsip/pjsip_resolver.c
@@ -231,8 +231,13 @@ static int sip_resolve_handle_naptr(struct sip_resolve *resolve, const struct as
 		return -1;
 	}
 
+	/* It is possible for us to receive an explicit transport that is already IPv6, in that case
+	 * we can't turn it into an IPv6 transport and check. If it's not IPv6 though we need to check
+	 * for both IPv4 and IPv6 as PJSIP does not provide enough differentiation to know that we
+	 * want only IPv4.
+	 */
 	if (!sip_transport_is_available(transport) &&
-		!sip_transport_is_available(transport + PJSIP_TRANSPORT_IPV6)) {
+		(!(transport & PJSIP_TRANSPORT_IPV6) && !sip_transport_is_available(transport + PJSIP_TRANSPORT_IPV6))) {
 		ast_debug(2, "[%p] NAPTR service %s skipped as transport is unavailable\n",
 			resolve, service);
 		return -1;
@@ -343,13 +348,19 @@ static void sip_resolve_callback(const struct ast_dns_query_set *query_set)
 				/* SRV records just create new queries for AAAA+A, nothing fancy */
 				ast_debug(2, "[%p] SRV record received on target '%s'\n", resolve, ast_dns_query_get_name(query));
 
-				if (sip_transport_is_available(target->transport + PJSIP_TRANSPORT_IPV6)) {
+				/* If an explicit IPv6 target transport has been requested look for only AAAA records */
+				if (target->transport & PJSIP_TRANSPORT_IPV6) {
+					sip_resolve_add(resolve, ast_dns_srv_get_host(record), ns_t_aaaa, ns_c_in, target->transport,
+						ast_dns_srv_get_port(record));
+					have_srv = 1;
+				} else if (sip_transport_is_available(target->transport + PJSIP_TRANSPORT_IPV6)) {
 					sip_resolve_add(resolve, ast_dns_srv_get_host(record), ns_t_aaaa, ns_c_in, target->transport + PJSIP_TRANSPORT_IPV6,
 						ast_dns_srv_get_port(record));
 					have_srv = 1;
 				}
 
-				if (sip_transport_is_available(target->transport)) {
+				if (!(target->transport & PJSIP_TRANSPORT_IPV6) &&
+					sip_transport_is_available(target->transport)) {
 					sip_resolve_add(resolve, ast_dns_srv_get_host(record), ns_t_a, ns_c_in, target->transport,
 						ast_dns_srv_get_port(record));
 					have_srv = 1;
@@ -365,14 +376,20 @@ static void sip_resolve_callback(const struct ast_dns_query_set *query_set)
 					continue;
 				}
 
-				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_UDP) {
-					added = sip_resolve_handle_naptr(resolve, record, "sip+d2u", PJSIP_TRANSPORT_UDP);
+				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_UDP ||
+					target->transport == PJSIP_TRANSPORT_UDP6) {
+					added = sip_resolve_handle_naptr(resolve, record, "sip+d2u",
+						target->transport == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_UDP : target->transport);
 				}
-				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_TCP) {
-					added = sip_resolve_handle_naptr(resolve, record, "sip+d2t", PJSIP_TRANSPORT_TCP);
+				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_TCP ||
+					target->transport == PJSIP_TRANSPORT_TCP6) {
+					added = sip_resolve_handle_naptr(resolve, record, "sip+d2t",
+						target->transport == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_TCP : target->transport);
 				}
-				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_TLS) {
-					added = sip_resolve_handle_naptr(resolve, record, "sips+d2t", PJSIP_TRANSPORT_TLS);
+				if (target->transport == PJSIP_TRANSPORT_UNSPECIFIED || target->transport == PJSIP_TRANSPORT_TLS ||
+					target->transport == PJSIP_TRANSPORT_TLS6) {
+					added = sip_resolve_handle_naptr(resolve, record, "sips+d2t",
+						target->transport == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_TLS : target->transport);
 				}
 
 				/* If this record was successfully handled then we need to limit ourselves to this order */
@@ -533,25 +550,39 @@ static void sip_resolve(pjsip_resolver_t *resolver, pj_pool_t *pool, const pjsip
 	if (!target->addr.port) {
 		char srv[NI_MAXHOST];
 
+		/* When resolving addresses PJSIP can request an explicit transport type. It will explicitly
+		 * request an IPv6 transport if a message has been tagged to use an explicitly IPv6 transport.
+		 * For other cases it can be left unspecified OR an explicit non-IPv6 transport can be requested.
+		 * In the case where a non-IPv6 transport is requested there is no way to differentiate between
+		 * a transport being requested as part of a SIP URI (sip:test.com;transport=tcp) and a message
+		 * being tagged with a specific IPv4 transport. In this case we look for both IPv4 and IPv6 addresses.
+		 * If a message has been tagged with a specific IPv4 transport the IPv6 addresses will simply
+		 * be discarded. The code below and elsewhere handles the case where we know they requested IPv6
+		 * explicitly and only looks for IPv6 records.
+		 */
+
 		res |= sip_resolve_add(resolve, host, ns_t_naptr, ns_c_in, type, 0);
 
-		if ((type == PJSIP_TRANSPORT_TLS || type == PJSIP_TRANSPORT_UNSPECIFIED) &&
-			(sip_transport_is_available(PJSIP_TRANSPORT_TLS) ||
-				sip_transport_is_available(PJSIP_TRANSPORT_TLS6))) {
+		if (type == PJSIP_TRANSPORT_UNSPECIFIED ||
+			(type == PJSIP_TRANSPORT_TLS && sip_transport_is_available(PJSIP_TRANSPORT_TLS)) ||
+			(type == PJSIP_TRANSPORT_TLS6 && sip_transport_is_available(PJSIP_TRANSPORT_TLS6))) {
 			snprintf(srv, sizeof(srv), "_sips._tcp.%s", host);
-			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in, PJSIP_TRANSPORT_TLS, 0);
+			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in,
+				type == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_TLS : type, 0);
 		}
-		if ((type == PJSIP_TRANSPORT_TCP || type == PJSIP_TRANSPORT_UNSPECIFIED) &&
-			(sip_transport_is_available(PJSIP_TRANSPORT_TCP) ||
-				sip_transport_is_available(PJSIP_TRANSPORT_TCP6))) {
+		if (type == PJSIP_TRANSPORT_UNSPECIFIED ||
+			(type == PJSIP_TRANSPORT_TCP && sip_transport_is_available(PJSIP_TRANSPORT_TCP)) ||
+			(type == PJSIP_TRANSPORT_TCP6 && sip_transport_is_available(PJSIP_TRANSPORT_TCP6))) {
 			snprintf(srv, sizeof(srv), "_sip._tcp.%s", host);
-			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in, PJSIP_TRANSPORT_TCP, 0);
+			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in,
+				type == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_TCP : type, 0);
 		}
-		if ((type == PJSIP_TRANSPORT_UDP || type == PJSIP_TRANSPORT_UNSPECIFIED) &&
-			(sip_transport_is_available(PJSIP_TRANSPORT_UDP) ||
-				sip_transport_is_available(PJSIP_TRANSPORT_UDP6))) {
+		if (type == PJSIP_TRANSPORT_UNSPECIFIED ||
+			(type == PJSIP_TRANSPORT_UDP && sip_transport_is_available(PJSIP_TRANSPORT_UDP)) ||
+			(type == PJSIP_TRANSPORT_UDP6 && sip_transport_is_available(PJSIP_TRANSPORT_UDP6))) {
 			snprintf(srv, sizeof(srv), "_sip._udp.%s", host);
-			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in, PJSIP_TRANSPORT_UDP, 0);
+			res |= sip_resolve_add(resolve, srv, ns_t_srv, ns_c_in,
+				type == PJSIP_TRANSPORT_UNSPECIFIED ? PJSIP_TRANSPORT_UDP : type, 0);
 		}
 	}