diff --git a/include/linux/socket.h b/include/linux/socket.h
index c3322eb3d686..3b262487ec06 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -168,7 +168,7 @@ static inline struct cmsghdr * cmsg_nxthdr (struct msghdr *__msg, struct cmsghdr
 	return __cmsg_nxthdr(__msg->msg_control, __msg->msg_controllen, __cmsg);
 }
 
-static inline size_t msg_data_left(struct msghdr *msg)
+static inline size_t msg_data_left(const struct msghdr *msg)
 {
 	return iov_iter_count(&msg->msg_iter);
 }