diff --git a/pre_commit/commands/install_uninstall.py b/pre_commit/commands/install_uninstall.py
index e27c5b2c..a5df9312 100644
--- a/pre_commit/commands/install_uninstall.py
+++ b/pre_commit/commands/install_uninstall.py
@@ -39,7 +39,7 @@ def _hook_paths(hook_type):
 
 
 def is_our_script(filename):
-    if not os.path.exists(filename):
+    if not os.path.exists(filename):  # pragma: windows no cover (symlink)
         return False
     with io.open(filename) as f:
         contents = f.read()
diff --git a/pre_commit/languages/docker.py b/pre_commit/languages/docker.py
index 35b2eda0..e5f3a36b 100644
--- a/pre_commit/languages/docker.py
+++ b/pre_commit/languages/docker.py
@@ -72,7 +72,7 @@ def install_environment(
         os.mkdir(directory)
 
 
-def docker_cmd():
+def docker_cmd():  # pragma: windows no cover
     return (
         'docker', 'run',
         '--rm',
diff --git a/tests/languages/helpers_test.py b/tests/languages/helpers_test.py
index b3360820..831e0d59 100644
--- a/tests/languages/helpers_test.py
+++ b/tests/languages/helpers_test.py
@@ -34,6 +34,15 @@ def test_failed_setup_command_does_not_unicode_error():
         helpers.run_setup_cmd(Prefix('.'), (sys.executable, '-c', script))
 
 
+def test_assert_no_additional_deps():
+    with pytest.raises(AssertionError) as excinfo:
+        helpers.assert_no_additional_deps('lang', ['hmmm'])
+    msg, = excinfo.value.args
+    assert msg == (
+        'For now, pre-commit does not support additional_dependencies for lang'
+    )
+
+
 SERIAL_FALSE = auto_namedtuple(require_serial=False)
 SERIAL_TRUE = auto_namedtuple(require_serial=True)
 
diff --git a/tests/prefix_test.py b/tests/prefix_test.py
index 728b5df4..2806cff1 100644
--- a/tests/prefix_test.py
+++ b/tests/prefix_test.py
@@ -38,3 +38,9 @@ def test_exists(tmpdir):
     assert not Prefix(str(tmpdir)).exists('foo')
     tmpdir.ensure('foo')
     assert Prefix(str(tmpdir)).exists('foo')
+
+
+def test_star(tmpdir):
+    for f in ('a.txt', 'b.txt', 'c.py'):
+        tmpdir.join(f).ensure()
+    assert set(Prefix(str(tmpdir)).star('.txt')) == {'a.txt', 'b.txt'}
diff --git a/tests/repository_test.py b/tests/repository_test.py
index 0286423b..eecf67b6 100644
--- a/tests/repository_test.py
+++ b/tests/repository_test.py
@@ -141,7 +141,7 @@ def test_versioned_python_hook(tempdir_factory, store):
     )
 
 
-@skipif_cant_run_docker
+@skipif_cant_run_docker  # pragma: windows no cover
 def test_run_a_docker_hook(tempdir_factory, store):
     _test_hook_repo(
         tempdir_factory, store, 'docker_hooks_repo',
@@ -150,7 +150,7 @@ def test_run_a_docker_hook(tempdir_factory, store):
     )
 
 
-@skipif_cant_run_docker
+@skipif_cant_run_docker  # pragma: windows no cover
 def test_run_a_docker_hook_with_entry_args(tempdir_factory, store):
     _test_hook_repo(
         tempdir_factory, store, 'docker_hooks_repo',
@@ -159,7 +159,7 @@ def test_run_a_docker_hook_with_entry_args(tempdir_factory, store):
     )
 
 
-@skipif_cant_run_docker
+@skipif_cant_run_docker  # pragma: windows no cover
 def test_run_a_failing_docker_hook(tempdir_factory, store):
     _test_hook_repo(
         tempdir_factory, store, 'docker_hooks_repo',
@@ -169,7 +169,7 @@ def test_run_a_failing_docker_hook(tempdir_factory, store):
     )
 
 
-@skipif_cant_run_docker
+@skipif_cant_run_docker  # pragma: windows no cover
 @pytest.mark.parametrize('hook_id', ('echo-entrypoint', 'echo-cmd'))
 def test_run_a_docker_image_hook(tempdir_factory, store, hook_id):
     _test_hook_repo(
@@ -242,7 +242,7 @@ def test_system_hook_with_spaces(tempdir_factory, store):
     )
 
 
-@skipif_cant_run_swift
+@skipif_cant_run_swift  # pragma: windows no cover
 def test_swift_hook(tempdir_factory, store):
     _test_hook_repo(
         tempdir_factory, store, 'swift_hooks_repo',
@@ -386,7 +386,7 @@ class TestPygrep(object):
         assert (ret, out) == (0, b'')
 
 
-@xfailif_no_pcre_support
+@xfailif_no_pcre_support  # pragma: windows no cover
 class TestPCRE(TestPygrep):
     """organized as a class for xfailing pcre"""
     language = 'pcre'
diff --git a/tox.ini b/tox.ini
index 52f3d3ee..aaeadc28 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,8 +9,7 @@ passenv = GOROOT HOME HOMEPATH PROGRAMDATA TERM
 commands =
     coverage erase
     coverage run -m pytest {posargs:tests}
-    # TODO: change to 100
-    coverage report --fail-under 99
+    coverage report --fail-under 100
     pre-commit run --all-files
 
 [testenv:venv]