diff --git a/zebra/ioctl.c b/zebra/ioctl.c
index 56de810..4137acf 100644
--- a/zebra/ioctl.c
+++ b/zebra/ioctl.c
@@ -75,7 +75,7 @@
 }
 
 #ifdef HAVE_IPV6
-int
+static int
 if_ioctl_ipv6 (u_long request, caddr_t buffer)
 {
   int sock;