diff --git a/testing/fixtures.py b/testing/fixtures.py
index 287eb309..247d2c4c 100644
--- a/testing/fixtures.py
+++ b/testing/fixtures.py
@@ -18,6 +18,7 @@ from pre_commit.clientlib import CONFIG_SCHEMA
 from pre_commit.clientlib import load_manifest
 from pre_commit.util import cmd_output
 from testing.util import get_resource_path
+from testing.util import git_commit
 
 
 def copy_tree_to_path(src_dir, dest_dir):
@@ -48,7 +49,7 @@ def make_repo(tempdir_factory, repo_source):
     path = git_dir(tempdir_factory)
     copy_tree_to_path(get_resource_path(repo_source), path)
     cmd_output('git', 'add', '.', cwd=path)
-    cmd_output('git', 'commit', '--no-gpg-sign', '-m', 'Add hooks', cwd=path)
+    git_commit('Add hooks', cwd=path)
     return path
 
 
@@ -63,11 +64,7 @@ def modify_manifest(path):
     yield manifest
     with io.open(manifest_path, 'w') as manifest_file:
         manifest_file.write(ordered_dump(manifest, **C.YAML_DUMP_KWARGS))
-    cmd_output(
-        'git', 'commit', '--no-gpg-sign', '-am',
-        'update {}'.format(C.MANIFEST_FILE),
-        cwd=path,
-    )
+    git_commit('update {}'.format(C.MANIFEST_FILE), cwd=path)
 
 
 @contextlib.contextmanager
@@ -82,9 +79,7 @@ def modify_config(path='.', commit=True):
     with io.open(config_path, 'w', encoding='UTF-8') as config_file:
         config_file.write(ordered_dump(config, **C.YAML_DUMP_KWARGS))
     if commit:
-        cmd_output(
-            'git', 'commit', '--no-gpg-sign', '-am', 'update config', cwd=path,
-        )
+        git_commit('update config', cwd=path)
 
 
 def config_with_local_hooks():
@@ -140,19 +135,13 @@ def write_config(directory, config, config_file=C.CONFIG_FILE):
 def add_config_to_repo(git_path, config, config_file=C.CONFIG_FILE):
     write_config(git_path, config, config_file=config_file)
     cmd_output('git', 'add', config_file, cwd=git_path)
-    cmd_output(
-        'git', 'commit', '--no-gpg-sign', '-m', 'Add hooks config',
-        cwd=git_path,
-    )
+    git_commit('Add hooks config', cwd=git_path)
     return git_path
 
 
 def remove_config_from_repo(git_path, config_file=C.CONFIG_FILE):
     cmd_output('git', 'rm', config_file, cwd=git_path)
-    cmd_output(
-        'git', 'commit', '--no-gpg-sign', '-m', 'Remove hooks config',
-        cwd=git_path,
-    )
+    git_commit('Remove hooks config', cwd=git_path)
     return git_path
 
 
diff --git a/testing/util.py b/testing/util.py
index ed38affe..0673a2e9 100644
--- a/testing/util.py
+++ b/testing/util.py
@@ -133,3 +133,18 @@ def cwd(path):
         yield
     finally:
         os.chdir(original_cwd)
+
+
+def git_commit(msg, *_args, **kwargs):
+    args = ['git']
+    config = kwargs.pop('config', None)
+    if config is not None:
+        args.extend(['-C', config])
+    args.append('commit')
+    if msg is not None:
+        args.extend(['-m', msg])
+    if '--allow-empty' not in _args:
+        args.append('--allow-empty')
+    if '--no-gpg-sign' not in _args:
+        args.append('--no-gpg-sign')
+    return cmd_output(*(tuple(args) + tuple(_args)), **kwargs)
diff --git a/tests/commands/autoupdate_test.py b/tests/commands/autoupdate_test.py
index 34c7292b..583cacec 100644
--- a/tests/commands/autoupdate_test.py
+++ b/tests/commands/autoupdate_test.py
@@ -21,6 +21,7 @@ from testing.fixtures import make_config_from_repo
 from testing.fixtures import make_repo
 from testing.fixtures import write_config
 from testing.util import get_resource_path
+from testing.util import git_commit
 
 
 @pytest.fixture
@@ -59,11 +60,11 @@ def test_autoupdate_old_revision_broken(tempdir_factory, in_tmpdir, store):
     config = make_config_from_repo(path, check=False)
 
     cmd_output('git', 'mv', C.MANIFEST_FILE, 'nope.yaml', cwd=path)
-    cmd_output('git', 'commit', '-m', 'simulate old repo', cwd=path)
+    git_commit('simulate old repo', cwd=path)
     # Assume this is the revision the user's old repository was at
     rev = git.head_rev(path)
     cmd_output('git', 'mv', 'nope.yaml', C.MANIFEST_FILE, cwd=path)
-    cmd_output('git', 'commit', '-m', 'move hooks file', cwd=path)
+    git_commit('move hooks file', cwd=path)
     update_rev = git.head_rev(path)
 
     config['rev'] = rev
@@ -84,7 +85,7 @@ def out_of_date_repo(tempdir_factory):
     original_rev = git.head_rev(path)
 
     # Make a commit
-    cmd_output('git', 'commit', '--allow-empty', '-m', 'foo', cwd=path)
+    git_commit('foo', cwd=path)
     head_rev = git.head_rev(path)
 
     yield auto_namedtuple(
@@ -239,7 +240,7 @@ def test_autoupdate_tagged_repo(tagged_repo, in_tmpdir, store):
 
 @pytest.fixture
 def tagged_repo_with_more_commits(tagged_repo):
-    cmd_output('git', 'commit', '--allow-empty', '-mfoo', cwd=tagged_repo.path)
+    git_commit('foo', cwd=tagged_repo.path)
     yield tagged_repo
 
 
@@ -263,7 +264,7 @@ def test_autoupdate_latest_no_config(out_of_date_repo, in_tmpdir, store):
     write_config('.', config)
 
     cmd_output('git', '-C', out_of_date_repo.path, 'rm', '-r', ':/')
-    cmd_output('git', '-C', out_of_date_repo.path, 'commit', '-m', 'rm')
+    git_commit('rm', config=out_of_date_repo.path)
 
     ret = autoupdate(C.CONFIG_FILE, store, tags_only=False)
     assert ret == 1
@@ -281,7 +282,7 @@ def hook_disappearing_repo(tempdir_factory):
         os.path.join(path, C.MANIFEST_FILE),
     )
     cmd_output('git', 'add', '.', cwd=path)
-    cmd_output('git', 'commit', '-m', 'Remove foo', cwd=path)
+    git_commit('Remove foo', cwd=path)
 
     yield auto_namedtuple(path=path, original_rev=original_rev)
 
diff --git a/tests/commands/install_uninstall_test.py b/tests/commands/install_uninstall_test.py
index ce74a2ea..3228b8da 100644
--- a/tests/commands/install_uninstall_test.py
+++ b/tests/commands/install_uninstall_test.py
@@ -28,6 +28,7 @@ from testing.fixtures import make_consuming_repo
 from testing.fixtures import remove_config_from_repo
 from testing.util import cmd_output_mocked_pre_commit_home
 from testing.util import cwd
+from testing.util import git_commit
 from testing.util import xfailif_no_symlink
 
 
@@ -109,7 +110,7 @@ def _get_commit_output(tempdir_factory, touch_file='foo', **kwargs):
     open(touch_file, 'a').close()
     cmd_output('git', 'add', touch_file)
     return cmd_output_mocked_pre_commit_home(
-        'git', 'commit', '-am', commit_msg, '--allow-empty',
+        'git', 'commit', '-am', commit_msg, '--allow-empty', '--no-gpg-sign',
         # git commit puts pre-commit to stderr
         stderr=subprocess.STDOUT,
         retcode=None,
@@ -151,7 +152,7 @@ def test_install_pre_commit_and_run_custom_path(tempdir_factory, store):
     path = make_consuming_repo(tempdir_factory, 'script_hooks_repo')
     with cwd(path):
         cmd_output('git', 'mv', C.CONFIG_FILE, 'custom-config.yaml')
-        cmd_output('git', 'commit', '-m', 'move pre-commit config')
+        git_commit('move pre-commit config')
         assert install('custom-config.yaml', store) == 0
 
         ret, output = _get_commit_output(tempdir_factory)
@@ -163,7 +164,7 @@ def test_install_in_submodule_and_run(tempdir_factory, store):
     src_path = make_consuming_repo(tempdir_factory, 'script_hooks_repo')
     parent_path = git_dir(tempdir_factory)
     cmd_output('git', 'submodule', 'add', src_path, 'sub', cwd=parent_path)
-    cmd_output('git', 'commit', '-m', 'foo', cwd=parent_path)
+    git_commit('foo', cwd=parent_path)
 
     sub_pth = os.path.join(parent_path, 'sub')
     with cwd(sub_pth):
@@ -193,7 +194,7 @@ def test_commit_am(tempdir_factory, store):
         # Make an unstaged change
         open('unstaged', 'w').close()
         cmd_output('git', 'add', '.')
-        cmd_output('git', 'commit', '-m', 'foo')
+        git_commit('foo')
         with io.open('unstaged', 'w') as foo_file:
             foo_file.write('Oh hai')
 
@@ -208,12 +209,12 @@ def test_unicode_merge_commit_message(tempdir_factory, store):
     with cwd(path):
         assert install(C.CONFIG_FILE, store) == 0
         cmd_output('git', 'checkout', 'master', '-b', 'foo')
-        cmd_output('git', 'commit', '--allow-empty', '-n', '-m', 'branch2')
+        git_commit('branch2', '-n')
         cmd_output('git', 'checkout', 'master')
         cmd_output('git', 'merge', 'foo', '--no-ff', '--no-commit', '-m', '☃')
         # Used to crash
         cmd_output_mocked_pre_commit_home(
-            'git', 'commit', '--no-edit',
+            'git', 'commit', '--no-edit', '--no-gpg-sign',
             tempdir_factory=tempdir_factory,
         )
 
@@ -246,8 +247,8 @@ def test_environment_not_sourced(tempdir_factory, store):
 
         # Use a specific homedir to ignore --user installs
         homedir = tempdir_factory.get()
-        ret, stdout, stderr = cmd_output(
-            'git', 'commit', '--allow-empty', '-m', 'foo',
+        ret, stdout, stderr = git_commit(
+            'foo',
             env={
                 'HOME': homedir,
                 'PATH': _path_without_us(),
diff --git a/tests/commands/run_test.py b/tests/commands/run_test.py
index 33920e5e..6d9a9592 100644
--- a/tests/commands/run_test.py
+++ b/tests/commands/run_test.py
@@ -479,7 +479,7 @@ def test_stdout_write_bug_py26(repo_with_failing_hook, store, tempdir_factory):
 
         # Have to use subprocess because pytest monkeypatches sys.stdout
         _, stdout, _ = cmd_output_mocked_pre_commit_home(
-            'git', 'commit', '-m', 'Commit!',
+            'git', 'commit', '-m', 'Commit!', '--no-gpg-sign',
             # git commit puts pre-commit to stderr
             stderr=subprocess.STDOUT,
             retcode=None,
@@ -508,7 +508,7 @@ def test_lots_of_files(store, tempdir_factory):
         install(C.CONFIG_FILE, store)
 
         cmd_output_mocked_pre_commit_home(
-            'git', 'commit', '-m', 'Commit!',
+            'git', 'commit', '-m', 'Commit!', '--no-gpg-sign',
             # git commit puts pre-commit to stderr
             stderr=subprocess.STDOUT,
             tempdir_factory=tempdir_factory,
diff --git a/tests/conftest.py b/tests/conftest.py
index 49fbf3fc..a4e3d991 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -19,6 +19,7 @@ from testing.fixtures import git_dir
 from testing.fixtures import make_consuming_repo
 from testing.fixtures import write_config
 from testing.util import cwd
+from testing.util import git_commit
 
 
 @pytest.fixture(autouse=True)
@@ -79,7 +80,7 @@ def _make_conflict():
     with io.open('foo_only_file', 'w') as foo_only_file:
         foo_only_file.write('foo')
     cmd_output('git', 'add', 'foo_only_file')
-    cmd_output('git', 'commit', '-m', 'conflict_file')
+    git_commit('conflict_file')
     cmd_output('git', 'checkout', 'origin/master', '-b', 'bar')
     with io.open('conflict_file', 'w') as conflict_file:
         conflict_file.write('harp\nddrp\n')
@@ -87,7 +88,7 @@ def _make_conflict():
     with io.open('bar_only_file', 'w') as bar_only_file:
         bar_only_file.write('bar')
     cmd_output('git', 'add', 'bar_only_file')
-    cmd_output('git', 'commit', '-m', 'conflict_file')
+    git_commit('conflict_file')
     cmd_output('git', 'merge', 'foo', retcode=None)
 
 
@@ -96,7 +97,7 @@ def in_merge_conflict(tempdir_factory):
     path = make_consuming_repo(tempdir_factory, 'script_hooks_repo')
     open(os.path.join(path, 'dummy'), 'a').close()
     cmd_output('git', 'add', 'dummy', cwd=path)
-    cmd_output('git', 'commit', '-m', 'Add config.', cwd=path)
+    git_commit('Add config.', cwd=path)
 
     conflict_path = tempdir_factory.get()
     cmd_output('git', 'clone', path, conflict_path)
@@ -109,7 +110,7 @@ def in_merge_conflict(tempdir_factory):
 def in_conflicting_submodule(tempdir_factory):
     git_dir_1 = git_dir(tempdir_factory)
     git_dir_2 = git_dir(tempdir_factory)
-    cmd_output('git', 'commit', '--allow-empty', '-minit!', cwd=git_dir_2)
+    git_commit('init!', cwd=git_dir_2)
     cmd_output('git', 'submodule', 'add', git_dir_2, 'sub', cwd=git_dir_1)
     with cwd(os.path.join(git_dir_1, 'sub')):
         _make_conflict()
@@ -135,7 +136,7 @@ def commit_msg_repo(tempdir_factory):
     write_config(path, config)
     with cwd(path):
         cmd_output('git', 'add', '.')
-        cmd_output('git', 'commit', '-m', 'add hooks')
+        git_commit('add hooks')
         yield path
 
 
diff --git a/tests/git_test.py b/tests/git_test.py
index 2a9bda4a..ebc7d16c 100644
--- a/tests/git_test.py
+++ b/tests/git_test.py
@@ -9,6 +9,7 @@ import pytest
 from pre_commit import git
 from pre_commit.error_handler import FatalError
 from pre_commit.util import cmd_output
+from testing.util import git_commit
 
 
 def test_get_root_at_root(in_git_dir):
@@ -104,11 +105,11 @@ def test_parse_merge_msg_for_conflicts(input, expected_output):
 
 
 def test_get_changed_files(in_git_dir):
-    cmd_output('git', 'commit', '--allow-empty', '-m', 'initial commit')
+    git_commit('initial commit')
     in_git_dir.join('a.txt').ensure()
     in_git_dir.join('b.txt').ensure()
     cmd_output('git', 'add', '.')
-    cmd_output('git', 'commit', '-m', 'add some files')
+    git_commit('add some files')
     files = git.get_changed_files('HEAD', 'HEAD^')
     assert files == ['a.txt', 'b.txt']
 
@@ -132,10 +133,10 @@ def test_zsplit(s, expected):
 
 @pytest.fixture
 def non_ascii_repo(in_git_dir):
-    cmd_output('git', 'commit', '--allow-empty', '-m', 'initial commit')
+    git_commit('initial commit')
     in_git_dir.join('интервью').ensure()
     cmd_output('git', 'add', '.')
-    cmd_output('git', 'commit', '--allow-empty', '-m', 'initial commit')
+    git_commit('initial commit')
     yield in_git_dir
 
 
diff --git a/tests/make_archives_test.py b/tests/make_archives_test.py
index 7f198322..287ac252 100644
--- a/tests/make_archives_test.py
+++ b/tests/make_archives_test.py
@@ -8,6 +8,7 @@ from pre_commit import git
 from pre_commit import make_archives
 from pre_commit.util import cmd_output
 from testing.fixtures import git_dir
+from testing.util import git_commit
 
 
 def test_make_archive(tempdir_factory):
@@ -16,13 +17,13 @@ def test_make_archive(tempdir_factory):
     # Add a files to the git directory
     open(os.path.join(git_path, 'foo'), 'a').close()
     cmd_output('git', 'add', '.', cwd=git_path)
-    cmd_output('git', 'commit', '-m', 'foo', cwd=git_path)
+    git_commit('foo', cwd=git_path)
     # We'll use this rev
     head_rev = git.head_rev(git_path)
     # And check that this file doesn't exist
     open(os.path.join(git_path, 'bar'), 'a').close()
     cmd_output('git', 'add', '.', cwd=git_path)
-    cmd_output('git', 'commit', '-m', 'bar', cwd=git_path)
+    git_commit('bar', cwd=git_path)
 
     # Do the thing
     archive_path = make_archives.make_archive(
diff --git a/tests/staged_files_only_test.py b/tests/staged_files_only_test.py
index 9f226a41..4e7cd9b1 100644
--- a/tests/staged_files_only_test.py
+++ b/tests/staged_files_only_test.py
@@ -15,6 +15,7 @@ from testing.auto_namedtuple import auto_namedtuple
 from testing.fixtures import git_dir
 from testing.util import cwd
 from testing.util import get_resource_path
+from testing.util import git_commit
 
 
 FOO_CONTENTS = '\n'.join(('1', '2', '3', '4', '5', '6', '7', '8', ''))
@@ -186,9 +187,9 @@ def test_img_conflict(img_staged, patch_dir):
 def submodule_with_commits(tempdir_factory):
     path = git_dir(tempdir_factory)
     with cwd(path):
-        cmd_output('git', 'commit', '--allow-empty', '-m', 'foo')
+        git_commit('foo')
         rev1 = cmd_output('git', 'rev-parse', 'HEAD')[1].strip()
-        cmd_output('git', 'commit', '--allow-empty', '-m', 'bar')
+        git_commit('bar')
         rev2 = cmd_output('git', 'rev-parse', 'HEAD')[1].strip()
         yield auto_namedtuple(path=path, rev1=rev1, rev2=rev2)
 
@@ -331,7 +332,7 @@ def test_autocrlf_commited_crlf(in_git_dir, patch_dir):
     cmd_output('git', 'config', '--local', 'core.autocrlf', 'false')
     _write(b'1\r\n2\r\n')
     cmd_output('git', 'add', 'foo')
-    cmd_output('git', 'commit', '-m', 'Check in crlf')
+    git_commit('Check in crlf')
 
     cmd_output('git', 'config', '--local', 'core.autocrlf', 'true')
     _write(b'1\r\n2\r\n\r\n\r\n\r\n')
diff --git a/tests/store_test.py b/tests/store_test.py
index bed0e901..e22c3aee 100644
--- a/tests/store_test.py
+++ b/tests/store_test.py
@@ -12,10 +12,10 @@ import six
 from pre_commit import git
 from pre_commit.store import _get_default_directory
 from pre_commit.store import Store
-from pre_commit.util import cmd_output
 from pre_commit.util import rmtree
 from testing.fixtures import git_dir
 from testing.util import cwd
+from testing.util import git_commit
 
 
 def test_our_session_fixture_works():
@@ -90,9 +90,9 @@ def test_does_not_recreate_if_directory_already_exists(store):
 def test_clone(store, tempdir_factory, log_info_mock):
     path = git_dir(tempdir_factory)
     with cwd(path):
-        cmd_output('git', 'commit', '--allow-empty', '-m', 'foo')
+        git_commit('foo')
         rev = git.head_rev(path)
-        cmd_output('git', 'commit', '--allow-empty', '-m', 'bar')
+        git_commit('bar')
 
     ret = store.clone(path, rev)
     # Should have printed some stuff