diff --git a/libc/include/netinet/in.h b/libc/include/netinet/in.h
index 7a4b6c7..01bf58e 100644
--- a/libc/include/netinet/in.h
+++ b/libc/include/netinet/in.h
@@ -32,6 +32,7 @@
 #include <linux/socket.h>
 #include <linux/in.h>
 #include <linux/in6.h>
+#include <linux/ipv6.h>
 #include <netinet/in6.h>
 
 __BEGIN_DECLS