diff --git a/lib/sockopt.c b/lib/sockopt.c
index d16c2be..1d4063a 100644
--- a/lib/sockopt.c
+++ b/lib/sockopt.c
@@ -260,7 +260,7 @@
  * interface index.
  * Not portable for IPv4, use only setsockopt_ifindex for v4.
  */
-int 
+static int 
 setsockopt_pktinfo (int af, int sock, int val)
 {
   int ret = -1;