diff --git a/socket/socket_sctp4b.c b/socket/socket_sctp4b.c
index 6d6b1cc..991224e 100644
--- a/socket/socket_sctp4b.c
+++ b/socket/socket_sctp4b.c
@@ -7,6 +7,7 @@
 #include "windoze.h"
 #include "socket.h"
 #include "ndelay.h"
+#include <errno.h>
 
 #ifndef EPROTONOSUPPORT
 #define EPROTONOSUPPORT EINVAL