diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f39150b..9467acf 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -23,6 +23,10 @@
     -   id: reorder-python-imports
         language_version: python2.7
 -   repo: https://github.com/asottile/pyupgrade
-    sha: v1.0.0
+    sha: v1.1.2
     hooks:
     -   id: pyupgrade
+-   repo: https://github.com/asottile/add-trailing-comma
+    sha: v0.3.0
+    hooks:
+    -   id: add-trailing-comma
diff --git a/pre_commit_hooks/check_added_large_files.py b/pre_commit_hooks/check_added_large_files.py
index 8d5f4c4..193b910 100644
--- a/pre_commit_hooks/check_added_large_files.py
+++ b/pre_commit_hooks/check_added_large_files.py
@@ -51,7 +51,7 @@ def main(argv=None):
     parser = argparse.ArgumentParser()
     parser.add_argument(
         'filenames', nargs='*',
-        help='Filenames pre-commit believes are changed.'
+        help='Filenames pre-commit believes are changed.',
     )
     parser.add_argument(
         '--maxkb', type=int, default=500,
diff --git a/pre_commit_hooks/check_ast.py b/pre_commit_hooks/check_ast.py
index 9809a3f..1090300 100644
--- a/pre_commit_hooks/check_ast.py
+++ b/pre_commit_hooks/check_ast.py
@@ -26,7 +26,7 @@ def check_ast(argv=None):
                 sys.version.partition(' ')[0],
             ))
             print('\n{}'.format(
-                '    ' + traceback.format_exc().replace('\n', '\n    ')
+                '    ' + traceback.format_exc().replace('\n', '\n    '),
             ))
             retval = 1
     return retval
diff --git a/pre_commit_hooks/check_case_conflict.py b/pre_commit_hooks/check_case_conflict.py
index 3d6cf74..0f78296 100644
--- a/pre_commit_hooks/check_case_conflict.py
+++ b/pre_commit_hooks/check_case_conflict.py
@@ -45,7 +45,7 @@ def main(argv=None):
     parser = argparse.ArgumentParser()
     parser.add_argument(
         'filenames', nargs='*',
-        help='Filenames pre-commit believes are changed.'
+        help='Filenames pre-commit believes are changed.',
     )
 
     args = parser.parse_args(argv)
diff --git a/pre_commit_hooks/check_docstring_first.py b/pre_commit_hooks/check_docstring_first.py
index 8e658a1..f2f5b72 100644
--- a/pre_commit_hooks/check_docstring_first.py
+++ b/pre_commit_hooks/check_docstring_first.py
@@ -1,4 +1,5 @@
 from __future__ import absolute_import
+from __future__ import print_function
 from __future__ import unicode_literals
 
 import argparse
@@ -30,7 +31,7 @@ def check_docstring_first(src, filename='<unknown>'):
                     '{}:{} Multiple module docstrings '
                     '(first docstring on line {}).'.format(
                         filename, sline, found_docstring_line,
-                    )
+                    ),
                 )
                 return 1
             elif found_code_line is not None:
@@ -38,7 +39,7 @@ def check_docstring_first(src, filename='<unknown>'):
                     '{}:{} Module docstring appears after code '
                     '(code seen on line {}).'.format(
                         filename, sline, found_code_line,
-                    )
+                    ),
                 )
                 return 1
             else:
diff --git a/pre_commit_hooks/check_merge_conflict.py b/pre_commit_hooks/check_merge_conflict.py
index 7d87efc..5035b6d 100644
--- a/pre_commit_hooks/check_merge_conflict.py
+++ b/pre_commit_hooks/check_merge_conflict.py
@@ -7,7 +7,7 @@ CONFLICT_PATTERNS = [
     b'<<<<<<< ',
     b'======= ',
     b'=======\n',
-    b'>>>>>>> '
+    b'>>>>>>> ',
 ]
 WARNING_MSG = 'Merge conflict string "{0}" found in {1}:{2}'
 
diff --git a/pre_commit_hooks/debug_statement_hook.py b/pre_commit_hooks/debug_statement_hook.py
index 902198f..d76e6e6 100644
--- a/pre_commit_hooks/debug_statement_hook.py
+++ b/pre_commit_hooks/debug_statement_hook.py
@@ -29,7 +29,7 @@ class ImportStatementParser(ast.NodeVisitor):
     def visit_ImportFrom(self, node):
         if node.module in DEBUG_STATEMENTS:
             self.debug_import_statements.append(
-                DebugStatement(node.module, node.lineno, node.col_offset)
+                DebugStatement(node.module, node.lineno, node.col_offset),
             )
 
 
@@ -52,7 +52,7 @@ def check_file_for_debug_statements(filename):
                     debug_statement.line,
                     debug_statement.col,
                     debug_statement.name,
-                )
+                ),
             )
         return 1
     else:
diff --git a/pre_commit_hooks/detect_aws_credentials.py b/pre_commit_hooks/detect_aws_credentials.py
index 42758f0..b2afd71 100644
--- a/pre_commit_hooks/detect_aws_credentials.py
+++ b/pre_commit_hooks/detect_aws_credentials.py
@@ -12,7 +12,7 @@ def get_aws_credential_files_from_env():
     files = set()
     for env_var in (
         'AWS_CONFIG_FILE', 'AWS_CREDENTIAL_FILE', 'AWS_SHARED_CREDENTIALS_FILE',
-        'BOTO_CONFIG'
+        'BOTO_CONFIG',
     ):
         if env_var in os.environ:
             files.add(os.environ[env_var])
@@ -23,7 +23,7 @@ def get_aws_secrets_from_env():
     """Extract AWS secrets from environment variables."""
     keys = set()
     for env_var in (
-        'AWS_SECRET_ACCESS_KEY', 'AWS_SECURITY_TOKEN', 'AWS_SESSION_TOKEN'
+        'AWS_SECRET_ACCESS_KEY', 'AWS_SECURITY_TOKEN', 'AWS_SESSION_TOKEN',
     ):
         if env_var in os.environ:
             keys.add(os.environ[env_var])
@@ -50,7 +50,7 @@ def get_aws_secrets_from_file(credentials_file):
     for section in parser.sections():
         for var in (
             'aws_secret_access_key', 'aws_security_token',
-            'aws_session_token'
+            'aws_session_token',
         ):
             try:
                 keys.add(parser.get(section, var))
@@ -93,13 +93,13 @@ def main(argv=None):
         help=(
             'Location of additional AWS credential files from which to get '
             'secret keys from'
-        )
+        ),
     )
     parser.add_argument(
         '--allow-missing-credentials',
         dest='allow_missing_credentials',
         action='store_true',
-        help='Allow hook to pass when no credentials are detected.'
+        help='Allow hook to pass when no credentials are detected.',
     )
     args = parser.parse_args(argv)
 
@@ -124,7 +124,7 @@ def main(argv=None):
         print(
             'No AWS keys were found in the configured credential files and '
             'environment variables.\nPlease ensure you have the correct '
-            'setting for --credentials-file'
+            'setting for --credentials-file',
         )
         return 2
 
diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
index 5e04230..bb7a3d0 100644
--- a/pre_commit_hooks/pretty_format_json.py
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -120,7 +120,7 @@ def pretty_format_json(argv=None):
         except simplejson.JSONDecodeError:
             print(
                 "Input File {} is not a valid JSON, consider using check-json"
-                .format(json_file)
+                .format(json_file),
             )
             return 1
 
diff --git a/pre_commit_hooks/tests_should_end_in_test.py b/pre_commit_hooks/tests_should_end_in_test.py
index 5f9bbac..9bea20d 100644
--- a/pre_commit_hooks/tests_should_end_in_test.py
+++ b/pre_commit_hooks/tests_should_end_in_test.py
@@ -11,7 +11,7 @@ def validate_files(argv=None):
     parser.add_argument('filenames', nargs='*')
     parser.add_argument(
         '--django', default=False, action='store_true',
-        help='Use Django-style test naming pattern (test*.py)'
+        help='Use Django-style test naming pattern (test*.py)',
     )
     args = parser.parse_args(argv)
 
@@ -27,8 +27,8 @@ def validate_files(argv=None):
             retcode = 1
             print(
                 '{} does not match pattern "{}"'.format(
-                    filename, test_name_pattern
-                )
+                    filename, test_name_pattern,
+                ),
             )
 
     return retcode
diff --git a/pre_commit_hooks/trailing_whitespace_fixer.py b/pre_commit_hooks/trailing_whitespace_fixer.py
index 1ae15a9..d44750d 100644
--- a/pre_commit_hooks/trailing_whitespace_fixer.py
+++ b/pre_commit_hooks/trailing_whitespace_fixer.py
@@ -36,7 +36,7 @@ def fix_trailing_whitespace(argv=None):
         const=[],
         default=argparse.SUPPRESS,
         dest='markdown_linebreak_ext',
-        help='Do not preserve linebreak spaces in Markdown'
+        help='Do not preserve linebreak spaces in Markdown',
     )
     parser.add_argument(
         '--markdown-linebreak-ext',
@@ -45,7 +45,7 @@ def fix_trailing_whitespace(argv=None):
         default=['md,markdown'],
         metavar='*|EXT[,EXT,...]',
         nargs='?',
-        help='Markdown extensions (or *) for linebreak spaces'
+        help='Markdown extensions (or *) for linebreak spaces',
     )
     parser.add_argument('filenames', nargs='*', help='Filenames to fix')
     args = parser.parse_args(argv)
@@ -69,7 +69,7 @@ def fix_trailing_whitespace(argv=None):
             parser.error(
                 "bad --markdown-linebreak-ext extension '{}' (has . / \\ :)\n"
                 "  (probably filename; use '--markdown-linebreak-ext=EXT')"
-                .format(ext)
+                .format(ext),
             )
 
     return_code = 0
diff --git a/tests/check_docstring_first_test.py b/tests/check_docstring_first_test.py
index f14880b..aa9898d 100644
--- a/tests/check_docstring_first_test.py
+++ b/tests/check_docstring_first_test.py
@@ -19,7 +19,7 @@ TESTS = (
         '"foo"\n',
         1,
         '{filename}:2 Module docstring appears after code '
-        '(code seen on line 1).\n'
+        '(code seen on line 1).\n',
     ),
     # Test double docstring
     (
@@ -28,7 +28,7 @@ TESTS = (
         '"fake docstring"\n',
         1,
         '{filename}:3 Multiple module docstrings '
-        '(first docstring on line 1).\n'
+        '(first docstring on line 1).\n',
     ),
     # Test multiple lines of code above
     (
diff --git a/tests/check_merge_conflict_test.py b/tests/check_merge_conflict_test.py
index 5a2e82a..a999aca 100644
--- a/tests/check_merge_conflict_test.py
+++ b/tests/check_merge_conflict_test.py
@@ -45,7 +45,7 @@ def f1_is_a_conflict_file(tmpdir):
             'child\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
         ) or f1.startswith(
             '<<<<<<< HEAD\n'
             'child\n'
@@ -53,7 +53,7 @@ def f1_is_a_conflict_file(tmpdir):
             '||||||| merged common ancestors\n'
             '=======\n'
             'parent\n'
-            '>>>>>>>'
+            '>>>>>>>',
         ) or f1.startswith(
             # .gitconfig with [pull] rebase = preserve causes a rebase which
             # flips parent / child
@@ -61,7 +61,7 @@ def f1_is_a_conflict_file(tmpdir):
             'parent\n'
             '=======\n'
             'child\n'
-            '>>>>>>>'
+            '>>>>>>>',
         )
         assert os.path.exists(os.path.join('.git', 'MERGE_MSG'))
         yield
diff --git a/tests/debug_statement_hook_test.py b/tests/debug_statement_hook_test.py
index c318346..7891eac 100644
--- a/tests/debug_statement_hook_test.py
+++ b/tests/debug_statement_hook_test.py
@@ -46,7 +46,7 @@ def test_returns_one_form_1(ast_with_debug_import_form_1):
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_1)
     assert visitor.debug_import_statements == [
-        DebugStatement('ipdb', 3, 0)
+        DebugStatement('ipdb', 3, 0),
     ]
 
 
@@ -54,7 +54,7 @@ def test_returns_one_form_2(ast_with_debug_import_form_2):
     visitor = ImportStatementParser()
     visitor.visit(ast_with_debug_import_form_2)
     assert visitor.debug_import_statements == [
-        DebugStatement('pudb', 3, 0)
+        DebugStatement('pudb', 3, 0),
     ]
 
 
diff --git a/tests/detect_aws_credentials_test.py b/tests/detect_aws_credentials_test.py
index 943a3f8..beb382f 100644
--- a/tests/detect_aws_credentials_test.py
+++ b/tests/detect_aws_credentials_test.py
@@ -21,14 +21,14 @@ from testing.util import get_resource_path
         (
             {
                 'AWS_DUMMY_KEY': '/foo', 'AWS_CONFIG_FILE': '/bar',
-                'AWS_CREDENTIAL_FILE': '/baz'
+                'AWS_CREDENTIAL_FILE': '/baz',
             },
             {'/bar', '/baz'}
         ),
         (
             {
                 'AWS_CONFIG_FILE': '/foo', 'AWS_CREDENTIAL_FILE': '/bar',
-                'AWS_SHARED_CREDENTIALS_FILE': '/baz'
+                'AWS_SHARED_CREDENTIALS_FILE': '/baz',
             },
             {'/foo', '/bar', '/baz'}
         ),
@@ -51,7 +51,7 @@ def test_get_aws_credentials_file_from_env(env_vars, values):
         ({'AWS_DUMMY_KEY': 'foo', 'AWS_SECRET_ACCESS_KEY': 'bar'}, {'bar'}),
         (
             {'AWS_SECRET_ACCESS_KEY': 'foo', 'AWS_SECURITY_TOKEN': 'bar'},
-            {'foo', 'bar'}
+            {'foo', 'bar'},
         ),
     ),
 )
@@ -66,7 +66,7 @@ def test_get_aws_secrets_from_env(env_vars, values):
     (
         (
             'aws_config_with_secret.ini',
-            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'}
+            {'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb'},
         ),
         ('aws_config_with_session_token.ini', {'foo'}),
         ('aws_config_with_secret_and_session_token.ini',
@@ -77,8 +77,8 @@ def test_get_aws_secrets_from_env(env_vars, values):
                 '7xebzorgm5143ouge9gvepxb2z70bsb2rtrh099e',
                 'z2rpgs5uit782eapz5l1z0y2lurtsyyk6hcfozlb',
                 'ixswosj8gz3wuik405jl9k3vdajsnxfhnpui38ez',
-                'foo'
-            }
+                'foo',
+            },
         ),
         ('aws_config_without_secrets.ini', set()),
         ('nonsense.txt', set()),
@@ -121,7 +121,7 @@ def test_non_existent_credentials(mock_secrets_env, mock_secrets_file, capsys):
     mock_secrets_file.return_value = set()
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
-        "--credentials-file=testing/resources/credentailsfilethatdoesntexist"
+        "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
     ))
     assert ret == 2
     out, _ = capsys.readouterr()
@@ -141,6 +141,6 @@ def test_non_existent_credentials_with_allow_flag(mock_secrets_env, mock_secrets
     ret = main((
         get_resource_path('aws_config_without_secrets.ini'),
         "--credentials-file=testing/resources/credentailsfilethatdoesntexist",
-        "--allow-missing-credentials"
+        "--allow-missing-credentials",
     ))
     assert ret == 0
diff --git a/tests/file_contents_sorter_test.py b/tests/file_contents_sorter_test.py
index 2c85c8a..1f9a14b 100644
--- a/tests/file_contents_sorter_test.py
+++ b/tests/file_contents_sorter_test.py
@@ -21,7 +21,7 @@ from pre_commit_hooks.file_contents_sorter import PASS
         (b'@\n-\n_\n#\n', FAIL, b'#\n-\n@\n_\n'),
         (b'extra\n\n\nwhitespace\n', FAIL, b'extra\nwhitespace\n'),
         (b'whitespace\n\n\nextra\n', FAIL, b'extra\nwhitespace\n'),
-    )
+    ),
 )
 def test_integration(input_s, expected_retval, output, tmpdir):
     path = tmpdir.join('file.txt')
diff --git a/tests/fix_encoding_pragma_test.py b/tests/fix_encoding_pragma_test.py
index d49f1ba..7288bfa 100644
--- a/tests/fix_encoding_pragma_test.py
+++ b/tests/fix_encoding_pragma_test.py
@@ -56,7 +56,7 @@ def test_integration_remove_ok(tmpdir):
             b'# -*- coding: utf-8 -*-\n'
             b'foo = "bar"\n'
         ),
-    )
+    ),
 )
 def test_ok_inputs(input_str):
     bytesio = io.BytesIO(input_str)
@@ -100,7 +100,7 @@ def test_ok_inputs(input_str):
         (b'#!/usr/bin/env python\n', b''),
         (b'#!/usr/bin/env python\n#coding: utf8\n', b''),
         (b'#!/usr/bin/env python\n# -*- coding: utf-8 -*-\n', b''),
-    )
+    ),
 )
 def test_not_ok_inputs(input_str, output):
     bytesio = io.BytesIO(input_str)
diff --git a/tests/requirements_txt_fixer_test.py b/tests/requirements_txt_fixer_test.py
index 3681cc6..dcf7a76 100644
--- a/tests/requirements_txt_fixer_test.py
+++ b/tests/requirements_txt_fixer_test.py
@@ -24,9 +24,9 @@ from pre_commit_hooks.requirements_txt_fixer import Requirement
         (
             b'-e git+ssh://git_url@tag#egg=ocflib\nDjango\nPyMySQL\n',
             FAIL,
-            b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n'
+            b'Django\n-e git+ssh://git_url@tag#egg=ocflib\nPyMySQL\n',
         ),
-    )
+    ),
 )
 def test_integration(input_s, expected_retval, output, tmpdir):
     path = tmpdir.join('file.txt')
diff --git a/tests/trailing_whitespace_fixer_test.py b/tests/trailing_whitespace_fixer_test.py
index eb2a1d0..a771e67 100644
--- a/tests/trailing_whitespace_fixer_test.py
+++ b/tests/trailing_whitespace_fixer_test.py
@@ -69,7 +69,7 @@ def test_markdown_linebreak_ext_opt(filename, input_s, output, tmpdir):
     path = tmpdir.join(filename)
     path.write(input_s)
     ret = fix_trailing_whitespace((
-        '--markdown-linebreak-ext=TxT', path.strpath
+        '--markdown-linebreak-ext=TxT', path.strpath,
     ))
     assert ret == 1
     assert path.read() == output