diff --git a/include/uapi/linux/in.h b/include/uapi/linux/in.h
index f243ce665f74..07a4cb149305 100644
--- a/include/uapi/linux/in.h
+++ b/include/uapi/linux/in.h
@@ -20,6 +20,7 @@
 #define _UAPI_LINUX_IN_H
 
 #include <linux/types.h>
+#include <linux/stddef.h>
 #include <linux/libc-compat.h>
 #include <linux/socket.h>