diff --git a/pyconfig.h.in b/pyconfig.h.in
index b24c4b0..95d71c9 100644
--- a/pyconfig.h.in
+++ b/pyconfig.h.in
@@ -539,6 +539,9 @@
 /* Define to 1 if you have the <netpacket/packet.h> header file. */
 #undef HAVE_NETPACKET_PACKET_H
 
+/* Define to 1 if you have the <net/if.h> header file. */
+#undef HAVE_NET_IF_H
+
 /* Define to 1 if you have the `nice' function. */
 #undef HAVE_NICE