1 files changed, 5 insertions, 0 deletions

diff --git a/util-linux/mount.c b/util-linux/mount.c
index 9f465f131..1c5137376 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -19,6 +19,9 @@
 #include <mntent.h>
 #include <syslog.h>
 #include <sys/mount.h>
+#ifndef MS_UNION
+# define MS_UNION       (1 << 8)
+#endif
 #ifndef MS_BIND
 # define MS_BIND        (1 << 12)
 #endif
@@ -177,6 +180,7 @@ static const int32_t mount_options[] = {
                 /* "loud"        */ ~MS_SILENT,
 
                 // action flags
+                /* "union"       */ MS_UNION,
                 /* "bind"        */ MS_BIND,
                 /* "move"        */ MS_MOVE,
                 /* "shared"      */ MS_SHARED,
@@ -231,6 +235,7 @@ static const char mount_option_str[] =
                 "loud\0"
 
                 // action flags
+                "union\0"
                 "bind\0"
                 "move\0"
                 "shared\0"