diff --git a/tests/autopep8_wrapper_test.py b/tests/autopep8_wrapper_test.py
index 9a395c9..a218e4b 100644
--- a/tests/autopep8_wrapper_test.py
+++ b/tests/autopep8_wrapper_test.py
@@ -2,7 +2,6 @@
 from __future__ import unicode_literals
 
 import io
-import os
 
 import pytest
 
@@ -25,16 +24,6 @@
     assert io.open(filename).read() == output_src
 
 
-@pytest.yield_fixture
-def in_tmpdir(tmpdir):
-    pwd = os.getcwd()
-    os.chdir(tmpdir.strpath)
-    try:
-        yield
-    finally:
-        os.chdir(pwd)
-
-
 @pytest.mark.usefixtures('in_tmpdir')
 def test_respects_config_file():
     with io.open('setup.cfg', 'w') as setup_cfg:
diff --git a/tests/check_added_large_files_test.py b/tests/check_added_large_files_test.py
index b72a315..b49f118 100644
--- a/tests/check_added_large_files_test.py
+++ b/tests/check_added_large_files_test.py
@@ -1,35 +1,35 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-from plumbum import local
-
 from pre_commit_hooks.check_added_large_files import find_large_added_files
 from pre_commit_hooks.check_added_large_files import main
+from pre_commit_hooks.util import cmd_output
+from testing.util import cwd
 from testing.util import write_file
 
 
 def test_nothing_added(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         assert find_large_added_files(['f.py'], 0) == 0
 
 
 def test_adding_something(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         # Should fail with max size of 0
         assert find_large_added_files(['f.py'], 0) == 1
 
 
 def test_add_something_giant(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', 'a' * 10000)
 
         # Should not fail when not added
         assert find_large_added_files(['f.py'], 0) == 0
 
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         # Should fail with strict bound
         assert find_large_added_files(['f.py'], 0) == 1
@@ -42,20 +42,20 @@
 
 
 def test_added_file_not_in_pre_commits_list(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         # Should pass even with a size of 0
         assert find_large_added_files(['g.py'], 0) == 0
 
 
 def test_integration(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         assert main(argv=[]) == 0
 
         write_file('f.py', 'a' * 10000)
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         # Should not fail with default
         assert main(argv=['f.py']) == 0
diff --git a/tests/check_case_conflict_test.py b/tests/check_case_conflict_test.py
index 344725d..2a32918 100644
--- a/tests/check_case_conflict_test.py
+++ b/tests/check_case_conflict_test.py
@@ -1,66 +1,66 @@
 from __future__ import absolute_import
 from __future__ import unicode_literals
 
-from plumbum import local
-
 from pre_commit_hooks.check_case_conflict import find_conflicting_filenames
 from pre_commit_hooks.check_case_conflict import main
+from pre_commit_hooks.util import cmd_output
+from testing.util import cwd
 from testing.util import write_file
 
 
 def test_nothing_added(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         assert find_conflicting_filenames(['f.py']) == 0
 
 
 def test_adding_something(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         assert find_conflicting_filenames(['f.py']) == 0
 
 
 def test_adding_something_with_conflict(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
         write_file('F.py', "print('hello world')")
-        local['git']('add', 'F.py')
+        cmd_output('git', 'add', 'F.py')
 
         assert find_conflicting_filenames(['f.py', 'F.py']) == 1
 
 
 def test_added_file_not_in_pre_commits_list(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         assert find_conflicting_filenames(['g.py']) == 0
 
 
 def test_file_conflicts_with_committed_file(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
-        local['git']('commit', '--no-verify', '-m', 'Add f.py')
+        cmd_output('git', 'add', 'f.py')
+        cmd_output('git', 'commit', '--no-verify', '-m', 'Add f.py')
 
         write_file('F.py', "print('hello world')")
-        local['git']('add', 'F.py')
+        cmd_output('git', 'add', 'F.py')
 
         assert find_conflicting_filenames(['F.py']) == 1
 
 
 def test_integration(temp_git_dir):
-    with local.cwd(temp_git_dir):
+    with cwd(temp_git_dir):
         assert main(argv=[]) == 0
 
         write_file('f.py', "print('hello world')")
-        local['git']('add', 'f.py')
+        cmd_output('git', 'add', 'f.py')
 
         assert main(argv=['f.py']) == 0
 
         write_file('F.py', "print('hello world')")
-        local['git']('add', 'F.py')
+        cmd_output('git', 'add', 'F.py')
 
         assert main(argv=['F.py']) == 1
diff --git a/tests/conftest.py b/tests/conftest.py
index 157da6b..de9c2fe 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,11 +3,19 @@
 from __future__ import unicode_literals
 
 import pytest
-from plumbum import local
+
+from pre_commit_hooks.util import cmd_output
+from testing.util import cwd
+
+
+@pytest.yield_fixture
+def in_tmpdir(tmpdir):
+    with cwd(tmpdir.strpath):
+        yield tmpdir
 
 
 @pytest.yield_fixture
 def temp_git_dir(tmpdir):
     git_dir = tmpdir.join('gits').strpath
-    local['git']('init', git_dir)
+    cmd_output('git', 'init', git_dir)
     yield git_dir
diff --git a/tests/trailing_whitespace_fixer_test.py b/tests/trailing_whitespace_fixer_test.py
index bf508c0..e24a722 100644
--- a/tests/trailing_whitespace_fixer_test.py
+++ b/tests/trailing_whitespace_fixer_test.py
@@ -1,10 +1,12 @@
-from plumbum import local
+from __future__ import absolute_import
+from __future__ import unicode_literals
 
 from pre_commit_hooks.trailing_whitespace_fixer import fix_trailing_whitespace
+from testing.util import cwd
 
 
 def test_fixes_trailing_whitespace(tmpdir):
-    with local.cwd(tmpdir.strpath):
+    with cwd(tmpdir.strpath):
         for filename, contents in (
                 ('foo.py', 'foo \nbar \n'),
                 ('bar.py', 'bar\t\nbaz\t\n'),
diff --git a/tests/util_test.py b/tests/util_test.py
new file mode 100644
index 0000000..9b2d723
--- /dev/null
+++ b/tests/util_test.py
@@ -0,0 +1,17 @@
+from __future__ import absolute_import
+from __future__ import unicode_literals
+
+import pytest
+
+from pre_commit_hooks.util import CalledProcessError
+from pre_commit_hooks.util import cmd_output
+
+
+def test_raises_on_error():
+    with pytest.raises(CalledProcessError):
+        cmd_output('sh', '-c', 'exit 1')
+
+
+def test_output():
+    ret = cmd_output('sh', '-c', 'echo hi')
+    assert ret == 'hi\n'