diff --git a/include/9p.h b/include/9p.h
index b6e959b..9d98bba 100644
--- a/include/9p.h
+++ b/include/9p.h
@@ -204,6 +204,7 @@
 	int		nopipe;
 	int		srvfd;
 	int		leavefdsopen;	/* magic for acme win */
+	int		dotu;
 
 /* below is implementation-specific; don't use */
 	Fidpool*	fpool;
diff --git a/include/libc.h b/include/libc.h
index 8b0c43c..1f86742 100644
--- a/include/libc.h
+++ b/include/libc.h
@@ -638,6 +638,8 @@
 #define DMDEVICE	0x00800000	/* mode bit for device file (Unix, 9P2000.u) */
 #define DMNAMEDPIPE	0x00200000	/* mode bit for named pipe (Unix, 9P2000.u) */
 #define DMSOCKET	0x00100000	/* mode bit for socket (Unix, 9P2000.u) */
+#define DMSETUID	0x00080000	/* mode bit for setuid (Unix, 9P2000.u) */
+#define DMSETGID	0x00040000	/* mode bit for setgid (Unix, 9P2000.u) */
 
 #define DMREAD		0x4		/* mode bit for read permission */
 #define DMWRITE		0x2		/* mode bit for write permission */