--- /dev/null
+--- nfs-utils-1.1.5/utils/mount/mount.c~ 2009-03-05 12:42:56.000000000 +0100
++++ nfs-utils-1.1.5/utils/mount/mount.c 2009-05-20 16:44:08.581980119 +0200
+@@ -94,6 +94,7 @@
+ { "sync", 0, 0, MS_SYNCHRONOUS}, /* synchronous I/O */
+ { "async", 0, 1, MS_SYNCHRONOUS}, /* asynchronous I/O */
+ { "dirsync", 0, 0, MS_DIRSYNC}, /* synchronous directory modifications */
++ { "union", 0, 0, MS_UNION }, /* Union mount */
+ { "remount", 0, 0, MS_REMOUNT}, /* Alter flags of mounted FS */
+ { "bind", 0, 0, MS_BIND }, /* Remount part of tree elsewhere */
+ { "rbind", 0, 0, MS_BIND|MS_REC }, /* Idem, plus mounted subtrees */
+--- nfs-utils-1.1.5/utils/mount/mount_constants.h~ 2009-03-05 12:42:56.000000000 +0100
++++ nfs-utils-1.1.5/utils/mount/mount_constants.h 2009-05-20 16:42:50.292974566 +0200
+@@ -21,6 +21,9 @@
+ if we have a stack or plain mount - mount atop of it, forming a stack. */
+ #define MS_OVER 0x200 /* 512 */
+ #endif
++#ifndef MS_UNION
++#define MS_UNION 0x100 /* 256: Mount on top of a union */
++#endif
+ #ifndef MS_NOATIME
+ #define MS_NOATIME 0x400 /* 1024: Do not update access times. */
+ #endif