diff --git a/tcp_options.h b/tcp_options.h
index d8da5f3295c..2509f870d44 100644
--- a/tcp_options.h
+++ b/tcp_options.h
@@ -23,6 +23,7 @@
 
 #ifdef USE_TCP
 
+#include <netinet/in.h>
 #include <netinet/tcp.h>
 #ifndef NO_TCP_ASYNC
 #define TCP_ASYNC /* enabled async mode */