diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index f3e00c5..9de6a69 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -233,7 +233,8 @@
 			 */
 			do {
 				if (low <= snum && snum <= high &&
-				    !test_bit(snum >> udptable->log, bitmap))
+				    !test_bit(snum >> udptable->log, bitmap) &&
+				    !inet_is_reserved_local_port(snum))
 					goto found;
 				snum += rand;
 			} while (snum != first);