diff --git a/check_openvpn/tcp.h b/check_openvpn/tcp.h
index d896b2e..9b2537a 100644
--- a/check_openvpn/tcp.h
+++ b/check_openvpn/tcp.h
@@ -13,6 +13,11 @@
 #include <sys/socket.h>
 #include <netdb.h>
 #include <fcntl.h>
+
+#ifdef __FreeBSD__
+#include <netinet/in.h>
+#endif
+
 using namespace std;
 
 int createSocket();