include netdb.h if we use getprotobynumber
diff --git a/iptables-save.c b/iptables-save.c
index 422a8d2..3f6e074 100644
--- a/iptables-save.c
+++ b/iptables-save.c
@@ -13,6 +13,7 @@
 #include <string.h>
 #include <dlfcn.h>
 #include <time.h>
+#include <netdb.h>
 #include "libiptc/libiptc.h"
 #include "iptables.h"