diff --git a/tools/gclient_hook.py b/tools/gclient_hook.py
index ab79a6741..16389628c 100644
--- a/tools/gclient_hook.py
+++ b/tools/gclient_hook.py
@@ -3,11 +3,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from __future__ import absolute_import
+from __future__ import print_function
+from file_util import make_dir, write_file
 from gclient_util import *
 from gn_args import GetAllPlatformConfigs, GetConfigFileContents
-from file_util import make_dir, write_file
-import os, sys
 import issue_1999
+import os
+import sys
 
 # The CEF directory is the parent directory of _this_ script.
 cef_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), os.pardir))
@@ -22,21 +25,21 @@ elif sys.platform == 'darwin':
 elif sys.platform.startswith('linux'):
   platform = 'linux'
 else:
-  print 'Unknown operating system platform'
+  print('Unknown operating system platform')
   sys.exit()
 
-print "\nGenerating CEF version header file..."
+print("\nGenerating CEF version header file...")
 cmd = [
-    'python', 'tools/make_version_header.py', '--header',
+    sys.executable, 'tools/make_version_header.py', '--header',
     'include/cef_version.h'
 ]
 RunAction(cef_dir, cmd)
 
-print "\nPatching build configuration and source files for CEF..."
-cmd = ['python', 'tools/patcher.py']
+print("\nPatching build configuration and source files for CEF...")
+cmd = [sys.executable, 'tools/patcher.py']
 RunAction(cef_dir, cmd)
 
-print "\nGenerating CEF project files..."
+print("\nGenerating CEF project files...")
 
 gn_args = {}
 
@@ -133,13 +136,13 @@ for dir, config in configs.items():
   if platform == 'windows':
     issue_1999.apply(out_path)
 
-gn_dir = configs.keys()[0]
+gn_dir = list(configs.keys())[0]
 out_gn_path = os.path.join(src_dir, 'out', gn_dir)
 gn_path = os.path.join(out_gn_path, 'args.gn')
-print "\nGenerating CEF buildinfo header file..."
+print("\nGenerating CEF buildinfo header file...")
 cmd = [
-    'python', 'tools/make_config_header.py', '--header', 'include/cef_config.h',
-    '--cef_gn_config', gn_path
+    sys.executable, 'tools/make_config_header.py', '--header',
+    'include/cef_config.h', '--cef_gn_config', gn_path
 ]
 
 RunAction(cef_dir, cmd)
diff --git a/tools/gclient_util.py b/tools/gclient_util.py
index cdc787374..5a6da54ee 100644
--- a/tools/gclient_util.py
+++ b/tools/gclient_util.py
@@ -3,12 +3,14 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+from __future__ import absolute_import
+from __future__ import print_function
 import os, sys
 
 try:
   # depot_tools may already be in the import path.
   import gclient_utils
-except ImportError, e:
+except ImportError as e:
   # Search the PATH environment variable to find the depot_tools folder.
   depot_tools = None
   paths = os.environ.get('PATH').split(os.pathsep)
@@ -18,7 +20,7 @@ except ImportError, e:
       break
 
   if depot_tools is None:
-    print >> sys.stderr, 'Error: could not find depot_tools in PATH.'
+    print('Error: could not find depot_tools in PATH.', file=sys.stderr)
     sys.exit(2)
 
   # Add depot_tools to import path.
@@ -29,18 +31,12 @@ except ImportError, e:
 # Copied from gclient.py python code.
 def RunAction(dir, command):
   """Runs the action."""
-  if command[0] == 'python':
-    # If the hook specified "python" as the first item, the action is a
-    # Python script.  Run it by starting a new copy of the same
-    # interpreter.
-    command[0] = sys.executable
-
   try:
     gclient_utils.CheckCallAndFilter(
         command, cwd=dir, always_show_header=True, print_stdout=True)
-  except gclient_utils.Error, e:
+  except gclient_utils.Error as e:
     # Use a discrete exit status code of 2 to indicate that a hook action
     # failed.  Users of this script may wish to treat hook action failures
     # differently from VC failures.
-    print >> sys.stderr, 'Error: %s' % str(e)
+    print('Error: %s' % str(e), file=sys.stderr)
     sys.exit(2)
diff --git a/tools/issue_1999.py b/tools/issue_1999.py
index 85a1e51d2..6c27d7040 100644
--- a/tools/issue_1999.py
+++ b/tools/issue_1999.py
@@ -10,6 +10,9 @@
 #   import issue_1999
 #   issue_1999.apply(output_path)
 #
+from __future__ import absolute_import
+from __future__ import print_function
+from io import open
 import sys
 import os
 
@@ -82,9 +85,9 @@ def process_line(line):
 
 
 def process_file(path):
-  print "Applying issue #1999 fix to " + path
+  print("Applying issue #1999 fix to " + path)
 
-  with open(path) as f:
+  with open(path, 'r', encoding='utf-8') as f:
     content = f.read().splitlines()
 
   result = []
@@ -92,9 +95,14 @@ def process_file(path):
   for line in content:
     result.append(process_line(line))
 
-  with open(path, "w") as f:
-    f.write("\n".join(result))
-    f.write("\n")
+  with open(path, 'w', encoding='utf-8') as fp:
+    str = "\n".join(result) + "\n"
+    try:
+      # Python 2
+      fp.write(str.decode('utf-8'))
+    except Exception as e:
+      # Python 3
+      fp.write(str)
 
 
 def apply(confpath):