diff --git a/lib/sockunion.h b/lib/sockunion.h
index b91c571..3613073 100644
--- a/lib/sockunion.h
+++ b/lib/sockunion.h
@@ -94,6 +94,7 @@
 extern size_t family2addrsize(int family);
 extern size_t sockunion_get_addrlen(const union sockunion *);
 extern const u_char *sockunion_get_addr(const union sockunion *);
+extern unsigned short sockunion_get_port (const union sockunion *);
 extern void sockunion_set(union sockunion *, int family, const u_char *addr, size_t bytes);
 
 extern union sockunion *sockunion_str2su (const char *str);