diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c
index f0a735e86851..8274b85aa298 100644
--- a/net/netfilter/nf_nat_sip.c
+++ b/net/netfilter/nf_nat_sip.c
@@ -113,13 +113,26 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff,
 		newaddr = ct->tuplehash[!dir].tuple.src.u3;
 		newport = ct_sip_info->forced_dport ? :
 			  ct->tuplehash[!dir].tuple.src.u.udp.port;
+	} else if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.src.u3, addr) &&
+	    ct->tuplehash[dir].tuple.src.u.udp.port != port) {
+		newaddr = ct->tuplehash[!dir].tuple.dst.u3;
+		newport = 0;
+	} else if (nf_inet_addr_cmp(&ct->tuplehash[dir].tuple.dst.u3, addr) &&
+		   ct->tuplehash[dir].tuple.dst.u.udp.port != port) {
+		newaddr = ct->tuplehash[!dir].tuple.src.u3;
+		newport = 0;
 	} else
 		return 1;
 
 	if (nf_inet_addr_cmp(&newaddr, addr) && newport == port)
 		return 1;
 
-	buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, ntohs(newport));
+	if (newport == 0)
+		buflen = sip_sprintf_addr(ct, buffer, &newaddr, false);
+	else
+		buflen = sip_sprintf_addr_port(ct, buffer, &newaddr,
+					       ntohs(newport));
+
 	return mangle_packet(skb, protoff, dataoff, dptr, datalen,
 			     matchoff, matchlen, buffer, buflen);
 }