diff --git a/src/libthecore/socket.cpp b/src/libthecore/socket.cpp
index 753d435..db61f10 100644
--- a/src/libthecore/socket.cpp
+++ b/src/libthecore/socket.cpp
@@ -1,4 +1,5 @@
 #include "stdafx.h"
+#include <netinet/tcp.h>
 
 /* Forwards */
 void socket_lingeron(socket_t s);