diff --git a/netns.go b/netns.go
index 2ca0fee..df04d2a 100644
--- a/netns.go
+++ b/netns.go
@@ -61,7 +61,7 @@ func (ns *NsHandle) Close() error {
 	return nil
 }
 
-// Get an empty (closed) NsHandle
+// None gets an empty (closed) NsHandle.
 func None() NsHandle {
 	return NsHandle(-1)
 }
diff --git a/netns_linux.go b/netns_linux.go
index bf71c21..5dc2285 100644
--- a/netns_linux.go
+++ b/netns_linux.go
@@ -7,14 +7,24 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"runtime"
 	"strconv"
 	"strings"
 	"syscall"
 )
 
+// SYS_SETNS syscall allows changing the namespace of the current process.
+var SYS_SETNS = map[string]uintptr{
+	"386":     346,
+	"amd64":   308,
+	"arm64":   268,
+	"arm":     375,
+	"ppc64le": 350,
+	"s390x":   339,
+}[runtime.GOARCH]
+
+// Deprecated: use syscall pkg instead (go >= 1.5 needed).
 const (
-	// These constants belong in the syscall library but have not been
-	// added yet.
 	CLONE_NEWUTS  = 0x04000000 /* New utsname group? */
 	CLONE_NEWIPC  = 0x08000000 /* New ipcs */
 	CLONE_NEWUSER = 0x10000000 /* New user namespace */
diff --git a/netns_linux_386.go b/netns_linux_386.go
deleted file mode 100644
index 1d769bb..0000000
--- a/netns_linux_386.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,386
-
-package netns
-
-const (
-	SYS_SETNS = 346
-)
diff --git a/netns_linux_amd64.go b/netns_linux_amd64.go
deleted file mode 100644
index b124666..0000000
--- a/netns_linux_amd64.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,amd64
-
-package netns
-
-const (
-	SYS_SETNS = 308
-)
diff --git a/netns_linux_arm.go b/netns_linux_arm.go
deleted file mode 100644
index 9c74eb5..0000000
--- a/netns_linux_arm.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,arm
-
-package netns
-
-const (
-	SYS_SETNS = 375
-)
diff --git a/netns_linux_arm64.go b/netns_linux_arm64.go
deleted file mode 100644
index 741a302..0000000
--- a/netns_linux_arm64.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,arm64
-
-package netns
-
-const (
-	SYS_SETNS = 268
-)
diff --git a/netns_linux_ppc64le.go b/netns_linux_ppc64le.go
deleted file mode 100644
index c49eba5..0000000
--- a/netns_linux_ppc64le.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,ppc64le
-
-package netns
-
-const (
-	SYS_SETNS = 350
-)
diff --git a/netns_linux_s390x.go b/netns_linux_s390x.go
deleted file mode 100644
index cc13e62..0000000
--- a/netns_linux_s390x.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// +build linux,s390x
-
-package netns
-
-const (
-	SYS_SETNS = 339
-)