diff --git a/src/os/file.go b/src/os/file.go
index b47bf748a..0e20d1bf1 100644
--- a/src/os/file.go
+++ b/src/os/file.go
@@ -307,6 +307,17 @@ func (f *File) Sync() (err error) {
 	return
 }
 
+// Chmod changes the mode of the file to mode. If there is an error, it will be
+// of type *PathError.
+func (f *File) Chmod(mode FileMode) (err error) {
+	if f.handle == nil {
+		err = ErrClosed
+	} else {
+		err = f.chmod(mode)
+	}
+	return
+}
+
 // LinkError records an error during a link or symlink or rename system call and
 // the paths that caused it.
 type LinkError struct {
diff --git a/src/os/file_other.go b/src/os/file_other.go
index 4e8f859b7..75c033281 100644
--- a/src/os/file_other.go
+++ b/src/os/file_other.go
@@ -149,3 +149,7 @@ func (f *File) Truncate(size int64) (err error) {
 
 	return Truncate(f.name, size)
 }
+
+func (f *File) chmod(mode FileMode) error {
+	return ErrUnsupported
+}
diff --git a/src/os/file_unix.go b/src/os/file_unix.go
index d94b80cc3..fd4d464f5 100644
--- a/src/os/file_unix.go
+++ b/src/os/file_unix.go
@@ -151,6 +151,21 @@ func (f *File) Truncate(size int64) (err error) {
 	return Truncate(f.name, size)
 }
 
+func (f *File) chmod(mode FileMode) error {
+	if f.handle == nil {
+		return ErrClosed
+	}
+
+	longName := fixLongPath(f.name)
+	e := ignoringEINTR(func() error {
+		return syscall.Chmod(longName, syscallMode(mode))
+	})
+	if e != nil {
+		return &PathError{Op: "chmod", Path: f.name, Err: e}
+	}
+	return nil
+}
+
 // ReadAt reads up to len(b) bytes from the File starting at the given absolute offset.
 // It returns the number of bytes read and any error encountered, possibly io.EOF.
 // At end of file, Pread returns 0, io.EOF.
diff --git a/src/os/file_windows.go b/src/os/file_windows.go
index 9588cac76..022381dee 100644
--- a/src/os/file_windows.go
+++ b/src/os/file_windows.go
@@ -142,3 +142,7 @@ func isWindowsNulName(name string) bool {
 	}
 	return true
 }
+
+func (f *File) chmod(mode FileMode) error {
+	return ErrNotImplemented
+}