diff --git a/clang-format.py b/clang-format.py
index 1773dbd..1b1d365 100755
--- a/clang-format.py
+++ b/clang-format.py
@@ -1,5 +1,5 @@
-#!/usr/bin/env python2
-# -*- coding:utf-8 -*-
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 # Copyright 2017 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
@@ -114,7 +114,9 @@
   try:
     result = cros_build_lib.RunCommand(cmd=cmd,
                                        print_cmd=False,
-                                       redirect_stdout=True)
+                                       redirect_stdout=True,
+                                       encoding='utf-8',
+                                       errors='replace')
   except cros_build_lib.RunCommandError as e:
     print('clang-format failed:\n' + str(e), file=sys.stderr)
     print('\nPlease report this to the clang team.', file=sys.stderr)
diff --git a/pre-upload.py b/pre-upload.py
index 75f3fcd..0b8a055 100755
--- a/pre-upload.py
+++ b/pre-upload.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
@@ -1425,6 +1425,8 @@
   cmd_result = cros_build_lib.RunCommand(cmd=cmd,
                                          print_cmd=False,
                                          redirect_stdout=True,
+                                         encoding='utf-8',
+                                         errors='replace',
                                          combine_stdout_stderr=True,
                                          error_code_ok=True)
   if cmd_result.returncode:
@@ -1452,7 +1454,8 @@
   cmd = [os.path.join(hooks_dir, 'checkpatch.pl')] + options + ['-']
   cmd_result = cros_build_lib.RunCommand(
       cmd=cmd, print_cmd=False, input=_get_patch(commit).encode('utf-8'),
-      redirect_stdout=True, combine_stdout_stderr=True, error_code_ok=True)
+      redirect_stdout=True, combine_stdout_stderr=True, error_code_ok=True,
+      encoding='utf-8', errors='replace')
   if cmd_result.returncode:
     return HookFailure('checkpatch.pl errors/warnings\n\n' + cmd_result.output)
   return None
@@ -1622,6 +1625,8 @@
                                          input=os.devnull,
                                          redirect_stdout=True,
                                          combine_stdout_stderr=True,
+                                         encoding='utf-8',
+                                         errors='replace',
                                          error_code_ok=True)
   if cmd_result.returncode:
     stdout = cmd_result.output
diff --git a/pre-upload_unittest.py b/pre-upload_unittest.py
index daee112..26459f2 100755
--- a/pre-upload_unittest.py
+++ b/pre-upload_unittest.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 # Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be