diff --git a/tools/gtp-link.c b/tools/gtp-link.c
index 6979459..325a45f 100644
--- a/tools/gtp-link.c
+++ b/tools/gtp-link.c
@@ -75,6 +75,7 @@
 {
 	int fd1 = socket(family, SOCK_DGRAM, 0);
 	int fd2 = socket(family, SOCK_DGRAM, 0);
+	int one = 1;
 
 	if (fd1 < 0 || fd2 < 0)
 		return -1;