diff --git a/src/pkg/os/Makefile b/src/pkg/os/Makefile
index b69ac24f2a4..ebb1665d425 100644
--- a/src/pkg/os/Makefile
+++ b/src/pkg/os/Makefile
@@ -15,24 +15,28 @@ GOFILES=\
 	path.go\
 	proc.go\
 	stat_$(GOOS).go\
-	sys_$(GOOS).go\
 	time.go\
 	types.go\
 
 GOFILES_freebsd=\
 	file_unix.go\
+	sys_bsd.go\
 
 GOFILES_darwin=\
 	file_unix.go\
+	sys_bsd.go\
 
 GOFILES_linux=\
 	file_unix.go\
+	sys_linux.go\
 
 GOFILES_nacl=\
 	file_unix.go\
+	sys_nacl.go\
 
 GOFILES_mingw=\
 	file_mingw.go\
+	sys_mingw.go\
 
 GOFILES+=$(GOFILES_$(GOOS))
 
diff --git a/src/pkg/os/sys_darwin.go b/src/pkg/os/sys_bsd.go
similarity index 83%
rename from src/pkg/os/sys_darwin.go
rename to src/pkg/os/sys_bsd.go
index 2e3ab212796..188993b6961 100644
--- a/src/pkg/os/sys_darwin.go
+++ b/src/pkg/os/sys_bsd.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Darwin-specific
+// os code shared between *BSD systems including OS X (Darwin)
+// and FreeBSD.
 
 package os
 
diff --git a/src/pkg/os/sys_freebsd.go b/src/pkg/os/sys_freebsd.go
deleted file mode 100644
index c567f5c3586..00000000000
--- a/src/pkg/os/sys_freebsd.go
+++ /dev/null
@@ -1,16 +0,0 @@
-// Copyright 2009 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package os
-
-import "syscall"
-
-func Hostname() (name string, err Error) {
-	var errno int
-	name, errno = syscall.Sysctl("kern.hostname")
-	if errno != 0 {
-		return "", NewSyscallError("sysctl kern.hostname", errno)
-	}
-	return name, nil
-}