Index: src/protocols.h
--- src/protocols.h.orig
+++ src/protocols.h
@@ -24,6 +24,7 @@
 #define __PROTOCOLS_H__
 
 #include <pcap.h>
+#include <sys/socket.h>
 #include <net/if.h>
 
 #ifdef SOLARIS
@@ -207,7 +208,7 @@ struct protocol_def {
        end_t end;
 };
 
-struct protocol_def protocols[MAX_PROTOCOLS];
+extern struct protocol_def protocols[MAX_PROTOCOLS];
 
 void   protocol_init(void);
 int8_t protocol_register(u_int8_t, const char *, const char *, const char *,
