diff --git a/vendor/golang.org/x/sys/plan9/const_plan9.go b/vendor/golang.org/x/sys/plan9/const_plan9.go
new file mode 100644
index 0000000..b4e85a3
--- /dev/null
+++ b/vendor/golang.org/x/sys/plan9/const_plan9.go
@@ -0,0 +1,70 @@
+package plan9
+
+// Plan 9 Constants
+
+// Open modes
+const (
+	O_RDONLY  = 0
+	O_WRONLY  = 1
+	O_RDWR    = 2
+	O_TRUNC   = 16
+	O_CLOEXEC = 32
+	O_EXCL    = 0x1000
+)
+
+// Rfork flags
+const (
+	RFNAMEG  = 1 << 0
+	RFENVG   = 1 << 1
+	RFFDG    = 1 << 2
+	RFNOTEG  = 1 << 3
+	RFPROC   = 1 << 4
+	RFMEM    = 1 << 5
+	RFNOWAIT = 1 << 6
+	RFCNAMEG = 1 << 10
+	RFCENVG  = 1 << 11
+	RFCFDG   = 1 << 12
+	RFREND   = 1 << 13
+	RFNOMNT  = 1 << 14
+)
+
+// Qid.Type bits
+const (
+	QTDIR    = 0x80
+	QTAPPEND = 0x40
+	QTEXCL   = 0x20
+	QTMOUNT  = 0x10
+	QTAUTH   = 0x08
+	QTTMP    = 0x04
+	QTFILE   = 0x00
+)
+
+// Dir.Mode bits
+const (
+	DMDIR    = 0x80000000
+	DMAPPEND = 0x40000000
+	DMEXCL   = 0x20000000
+	DMMOUNT  = 0x10000000
+	DMAUTH   = 0x08000000
+	DMTMP    = 0x04000000
+	DMREAD   = 0x4
+	DMWRITE  = 0x2
+	DMEXEC   = 0x1
+)
+
+const (
+	STATMAX    = 65535
+	ERRMAX     = 128
+	STATFIXLEN = 49
+)
+
+// Mount and bind flags
+const (
+	MREPL   = 0x0000
+	MBEFORE = 0x0001
+	MAFTER  = 0x0002
+	MORDER  = 0x0003
+	MCREATE = 0x0004
+	MCACHE  = 0x0010
+	MMASK   = 0x0017
+)