--- a/config/nsinstall.py
+++ b/config/nsinstall.py
@@ -36,17 +36,17 @@ def _nsinstall_internal(argv):
                help="Link prefix (ignored)")
   p.add_option('-X', action="append", metavar="file",
                help="Ignore a file when installing a directory recursively.")
 
   # The remaining arguments are not used in our tree, thus they're not
   # implented.
   def BadArg(option, opt, value, parser):
     parser.error('option not supported: {0}'.format(opt))
-    
+
   p.add_option('-C', action="callback", metavar="CWD",
                callback=BadArg,
                help="NOT SUPPORTED")
   p.add_option('-o', action="callback", callback=BadArg,
                help="Set owner (NOT SUPPORTED)", metavar="owner")
   p.add_option('-g', action="callback", callback=BadArg,
                help="Set group (NOT SUPPORTED)", metavar="group")
 

--- a/config/tests/unit-nsinstall.py
+++ b/config/tests/unit-nsinstall.py
@@ -114,17 +114,17 @@ class TestNsinstall(unittest.TestCase):
         self.assertEqual(os.stat(testfile).st_mtime,
                          os.stat(destfile).st_mtime)
 
     if sys.platform != "win32":
         # can't run this test on windows, don't have real file modes there
         def test_nsinstall_m(self):
             "Test that nsinstall -m works (set mode)"
             testfile = self.touch("testfile")
-            mode = 0600
+            mode = 0o600
             os.chmod(testfile, mode)
             testdir = self.mkdirs("testdir")
             self.assertEqual(nsinstall(["-m", "{0:04o}"
                                         .format(mode), testfile, testdir]), 0)
             destfile = os.path.join(testdir, "testfile")
             self.assert_(os.path.isfile(destfile))
             self.assertEqual(os.stat(testfile).st_mode,
                              os.stat(destfile).st_mode)

--- a/configure.py
+++ b/configure.py
@@ -76,17 +76,17 @@ def config_status(config):
 if __name__ == '__main__':
     args = dict([(name, globals()[name]) for name in __all__])
     from mozbuild.config_status import config_status
     config_status(**args)
 ''')
 
     # Other things than us are going to run this file, so we need to give it
     # executable permissions.
-    os.chmod('config.status', 0755)
+    os.chmod('config.status', 0o755)
     if config.get('MOZ_BUILD_APP') != 'js' or config.get('JS_STANDALONE'):
         os.environ['WRITE_MOZINFO'] = '1'
         # Until we have access to the virtualenv from this script, execute
         # config.status externally, with the virtualenv python.
         return subprocess.call([config['PYTHON'], 'config.status'])
     return 0
 
 

--- a/python/mozbuild/mozpack/copier.py
+++ b/python/mozbuild/mozpack/copier.py
@@ -319,19 +319,19 @@ class FileCopier(FileRegistry):
                 if stat.S_ISLNK(st.st_mode):
                     # While we have remove_unaccounted, it doesn't apply
                     # to directory symlinks because if it did, our behavior
                     # could be very wrong.
                     os.remove(d)
                     os.mkdir(d)
 
             if not os.access(d, os.W_OK):
-                umask = os.umask(0077)
+                umask = os.umask(0o077)
                 os.umask(umask)
-                os.chmod(d, 0777 & ~umask)
+                os.chmod(d, 0o777 & ~umask)
 
         if isinstance(remove_unaccounted, FileRegistry):
             existing_files = set(os.path.normpath(os.path.join(destination, p))
                                  for p in remove_unaccounted.paths())
             existing_dirs = set(os.path.normpath(os.path.join(destination, p))
                                 for p in remove_unaccounted
                                          .required_directories())
             existing_dirs |= {os.path.normpath(destination)}
@@ -407,17 +407,17 @@ class FileCopier(FileRegistry):
 
         # Remove files no longer accounted for.
         if remove_unaccounted:
             for f in existing_files - dest_files:
                 # Windows requires write access to remove files.
                 if os.name == 'nt' and not os.access(f, os.W_OK):
                     # It doesn't matter what we set permissions to since we
                     # will remove this file shortly.
-                    os.chmod(f, 0600)
+                    os.chmod(f, 0o600)
 
                 os.remove(f)
                 result.removed_files.add(f)
 
         if not remove_empty_directories:
             return result
 
         # Figure out which directories can be removed. This is complicated
@@ -449,17 +449,17 @@ class FileCopier(FileRegistry):
         for d in sorted(remove_dirs, key=len, reverse=True):
             try:
                 try:
                     os.rmdir(d)
                 except OSError as e:
                     if e.errno in (errno.EPERM, errno.EACCES):
                         # Permissions may not allow deletion. So ensure write
                         # access is in place before attempting to rmdir again.
-                        os.chmod(d, 0700)
+                        os.chmod(d, 0o700)
                         os.rmdir(d)
                     else:
                         raise
             except OSError as e:
                 # If remove_unaccounted is a # FileRegistry, then we have a
                 # list of directories that may not be empty, so ignore rmdir
                 # ENOTEMPTY errors for them.
                 if (isinstance(remove_unaccounted, FileRegistry) and

--- a/python/mozbuild/mozpack/test/test_copier.py
+++ b/python/mozbuild/mozpack/test/test_copier.py
@@ -332,18 +332,18 @@ class TestFileCopier(TestWithTmpDir):
 
         p = self.tmppath('no_perms')
         with open(p, 'a'):
             pass
 
         # Make file and directory unwritable. Reminder: making a directory
         # unwritable prevents modifications (including deletes) from the list
         # of files in that directory.
-        os.chmod(p, 0400)
-        os.chmod(self.tmpdir, 0400)
+        os.chmod(p, 0o400)
+        os.chmod(self.tmpdir, 0o400)
 
         copier = FileCopier()
         copier.add('dummy', GeneratedFile('content'))
         result = copier.copy(self.tmpdir)
         self.assertEqual(result.removed_files_count, 1)
         self.assertFalse(os.path.exists(p))
 
     def test_no_remove(self):