diff --git a/php_linux.go b/php_linux.go
deleted file mode 100644
index 731dd70..0000000
--- a/php_linux.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// php2go functions
-
-package php2go
-
-import (
-	"syscall"
-)
-
-// Umask umask()
-func Umask(mask int) int {
-	return syscall.Umask(mask)
-}
-
-// DiskFreeSpace disk_free_space()
-func DiskFreeSpace(directory string) (uint64, error) {
-	fs := syscall.Statfs_t{}
-	err := syscall.Statfs(directory, &fs)
-	if err != nil {
-		return 0, err
-	}
-	return fs.Bfree * uint64(fs.Bsize), nil
-}
-
-// DiskTotalSpace disk_total_space()
-func DiskTotalSpace(directory string) (uint64, error) {
-	fs := syscall.Statfs_t{}
-	err := syscall.Statfs(directory, &fs)
-	if err != nil {
-		return 0, err
-	}
-	return fs.Blocks * uint64(fs.Bsize), nil
-}
diff --git a/php_darwin.go b/php_unix.go
similarity index 96%
rename from php_darwin.go
rename to php_unix.go
index 731dd70..90d6113 100644
--- a/php_darwin.go
+++ b/php_unix.go
@@ -1,5 +1,7 @@
 // php2go functions
 
+// +build linux darwin
+
 package php2go
 
 import (
diff --git a/php_windows.go b/php_windows.go
new file mode 100644
index 0000000..65f5fa5
--- /dev/null
+++ b/php_windows.go
@@ -0,0 +1,5 @@
+// php2go functions
+
+// +build windowns
+
+package php2go