diff --git a/os_testr/os_testr.py b/os_testr/ostestr.py
similarity index 77%
rename from os_testr/os_testr.py
rename to os_testr/ostestr.py
index 14a45bf..17ed1bd 100755
--- a/os_testr/os_testr.py
+++ b/os_testr/ostestr.py
@@ -23,6 +23,8 @@ import pbr.version
 from subunit import run as subunit_run
 from testtools import run as testtools_run
 
+from os_testr import regex_builder as rb
+
 
 __version__ = pbr.version.VersionInfo('os_testr').version_string()
 
@@ -95,91 +97,6 @@ def get_parser(args):
     return parser.parse_known_args(args)
 
 
-def _get_test_list(regex, env=None):
-    env = env or copy.deepcopy(os.environ)
-    proc = subprocess.Popen(['testr', 'list-tests', regex], env=env,
-                            stdout=subprocess.PIPE)
-    out = proc.communicate()[0]
-    raw_test_list = out.split('\n')
-    bad = False
-    test_list = []
-    exclude_list = ['OS_', 'CAPTURE', 'TEST_TIMEOUT', 'PYTHON',
-                    'subunit.run discover']
-    for line in raw_test_list:
-        for exclude in exclude_list:
-            if exclude in line:
-                bad = True
-                break
-            elif not line:
-                bad = True
-                break
-        if not bad:
-            test_list.append(line)
-        bad = False
-    return test_list
-
-
-def print_skips(regex, message):
-    test_list = _get_test_list(regex)
-    if test_list:
-        if message:
-            print(message)
-        else:
-            print('Skipped because of regex %s:' % regex)
-        for test in test_list:
-            print(test)
-        # Extra whitespace to separate
-        print('\n')
-
-
-def path_to_regex(path):
-    root, _ = os.path.splitext(path)
-    return root.replace('/', '.')
-
-
-def get_regex_from_whitelist_file(file_path):
-    lines = []
-    for line in open(file_path).read().splitlines():
-        split_line = line.strip().split('#')
-        # Before the # is the regex
-        line_regex = split_line[0].strip()
-        if line_regex:
-            lines.append(line_regex)
-    return '|'.join(lines)
-
-
-def construct_regex(blacklist_file, whitelist_file, regex, print_exclude):
-    if not blacklist_file:
-        exclude_regex = ''
-    else:
-        black_file = open(blacklist_file, 'r')
-        exclude_regex = ''
-        for line in black_file:
-            raw_line = line.strip()
-            split_line = raw_line.split('#')
-            # Before the # is the regex
-            line_regex = split_line[0].strip()
-            if len(split_line) > 1:
-                # After the # is a comment
-                comment = split_line[1].strip()
-            else:
-                comment = ''
-            if line_regex:
-                if print_exclude:
-                    print_skips(line_regex, comment)
-                if exclude_regex:
-                    exclude_regex = '|'.join([line_regex, exclude_regex])
-                else:
-                    exclude_regex = line_regex
-        if exclude_regex:
-            exclude_regex = "^((?!" + exclude_regex + ").)*$"
-    if regex:
-        exclude_regex += regex
-    if whitelist_file:
-        exclude_regex += '%s' % get_regex_from_whitelist_file(whitelist_file)
-    return exclude_regex
-
-
 def call_testr(regex, subunit, pretty, list_tests, slowest, parallel, concur,
                until_failure, color, others=None):
     others = others or []
@@ -206,7 +123,7 @@ def call_testr(regex, subunit, pretty, list_tests, slowest, parallel, concur,
     # This workaround is necessary because of lp bug 1411804 it's super hacky
     # and makes tons of unfounded assumptions, but it works for the most part
     if (subunit or pretty) and until_failure:
-        test_list = _get_test_list(regex, env)
+        test_list = rb._get_test_list(regex, env)
         count = 0
         failed = False
         if not test_list:
@@ -292,7 +209,7 @@ def _select_and_call_runner(opts, exclude_regex, others):
             return 2
         test_to_run = opts.no_discover or opts.pdb
         if test_to_run.find('/') != -1:
-            test_to_run = path_to_regex(test_to_run)
+            test_to_run = rb.path_to_regex(test_to_run)
         ec = call_subunit_run(test_to_run, opts.pretty, opts.subunit)
     return ec
 
@@ -318,13 +235,13 @@ def main():
         print(msg)
         exit(5)
     if opts.path:
-        regex = path_to_regex(opts.path)
+        regex = rb.path_to_regex(opts.path)
     else:
         regex = opts.regex
-    exclude_regex = construct_regex(opts.blacklist_file,
-                                    opts.whitelist_file,
-                                    regex,
-                                    opts.print_exclude)
+    exclude_regex = rb.construct_regex(opts.blacklist_file,
+                                       opts.whitelist_file,
+                                       regex,
+                                       opts.print_exclude)
     exit(_select_and_call_runner(opts, exclude_regex, others))
 
 if __name__ == '__main__':
diff --git a/os_testr/regex_builder.py b/os_testr/regex_builder.py
new file mode 100644
index 0000000..acba769
--- /dev/null
+++ b/os_testr/regex_builder.py
@@ -0,0 +1,102 @@
+# Copyright 2016 Hewlett-Packard Development Company, L.P.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+import copy
+import os
+import subprocess
+
+
+def _get_test_list(regex, env=None):
+    env = env or copy.deepcopy(os.environ)
+    proc = subprocess.Popen(['testr', 'list-tests', regex], env=env,
+                            stdout=subprocess.PIPE)
+    out = proc.communicate()[0]
+    raw_test_list = out.split('\n')
+    bad = False
+    test_list = []
+    exclude_list = ['OS_', 'CAPTURE', 'TEST_TIMEOUT', 'PYTHON',
+                    'subunit.run discover']
+    for line in raw_test_list:
+        for exclude in exclude_list:
+            if exclude in line:
+                bad = True
+                break
+            elif not line:
+                bad = True
+                break
+        if not bad:
+            test_list.append(line)
+        bad = False
+    return test_list
+
+
+def print_skips(regex, message):
+    test_list = _get_test_list(regex)
+    if test_list:
+        if message:
+            print(message)
+        else:
+            print('Skipped because of regex %s:' % regex)
+        for test in test_list:
+            print(test)
+        # Extra whitespace to separate
+        print('\n')
+
+
+def path_to_regex(path):
+    root, _ = os.path.splitext(path)
+    return root.replace('/', '.')
+
+
+def get_regex_from_whitelist_file(file_path):
+    lines = []
+    for line in open(file_path).read().splitlines():
+        split_line = line.strip().split('#')
+        # Before the # is the regex
+        line_regex = split_line[0].strip()
+        if line_regex:
+            lines.append(line_regex)
+    return '|'.join(lines)
+
+
+def construct_regex(blacklist_file, whitelist_file, regex, print_exclude):
+    if not blacklist_file:
+        exclude_regex = ''
+    else:
+        black_file = open(blacklist_file, 'r')
+        exclude_regex = ''
+        for line in black_file:
+            raw_line = line.strip()
+            split_line = raw_line.split('#')
+            # Before the # is the regex
+            line_regex = split_line[0].strip()
+            if len(split_line) > 1:
+                # After the # is a comment
+                comment = split_line[1].strip()
+            else:
+                comment = ''
+            if line_regex:
+                if print_exclude:
+                    print_skips(line_regex, comment)
+                if exclude_regex:
+                    exclude_regex = '|'.join([line_regex, exclude_regex])
+                else:
+                    exclude_regex = line_regex
+        if exclude_regex:
+            exclude_regex = "^((?!" + exclude_regex + ").)*$"
+    if regex:
+        exclude_regex += regex
+    if whitelist_file:
+        exclude_regex += '%s' % get_regex_from_whitelist_file(whitelist_file)
+    return exclude_regex
diff --git a/os_testr/tests/test_ostestr.py b/os_testr/tests/test_ostestr.py
new file mode 100644
index 0000000..df76ce6
--- /dev/null
+++ b/os_testr/tests/test_ostestr.py
@@ -0,0 +1,117 @@
+# -*- coding: utf-8 -*-
+
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+"""
+test_os_testr
+----------------------------------
+
+Tests for `os_testr` module.
+"""
+
+import mock
+
+from os_testr import ostestr as os_testr
+from os_testr.tests import base
+
+
+class TestGetParser(base.TestCase):
+    def test_pretty(self):
+        namespace = os_testr.get_parser(['--pretty'])
+        self.assertEqual(True, namespace[0].pretty)
+        namespace = os_testr.get_parser(['--no-pretty'])
+        self.assertEqual(False, namespace[0].pretty)
+        self.assertRaises(SystemExit, os_testr.get_parser,
+                          ['--no-pretty', '--pretty'])
+
+    def test_slowest(self):
+        namespace = os_testr.get_parser(['--slowest'])
+        self.assertEqual(True, namespace[0].slowest)
+        namespace = os_testr.get_parser(['--no-slowest'])
+        self.assertEqual(False, namespace[0].slowest)
+        self.assertRaises(SystemExit, os_testr.get_parser,
+                          ['--no-slowest', '--slowest'])
+
+    def test_parallel(self):
+        namespace = os_testr.get_parser(['--parallel'])
+        self.assertEqual(True, namespace[0].parallel)
+        namespace = os_testr.get_parser(['--serial'])
+        self.assertEqual(False, namespace[0].parallel)
+        self.assertRaises(SystemExit, os_testr.get_parser,
+                          ['--parallel', '--serial'])
+
+
+class TestCallers(base.TestCase):
+    def test_no_discover(self):
+        namespace = os_testr.get_parser(['-n', 'project.tests.foo'])
+
+        def _fake_exit(arg):
+            self.assertTrue(arg)
+
+        def _fake_run(*args, **kwargs):
+            return 'project.tests.foo' in args
+
+        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
+                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
+                mock.patch.object(os_testr,
+                                  'call_subunit_run',
+                                  side_effect=_fake_run):
+            os_testr.main()
+
+    def test_no_discover_path(self):
+        namespace = os_testr.get_parser(['-n', 'project/tests/foo'])
+
+        def _fake_exit(arg):
+            self.assertTrue(arg)
+
+        def _fake_run(*args, **kwargs):
+            return 'project.tests.foo' in args
+
+        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
+                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
+                mock.patch.object(os_testr,
+                                  'call_subunit_run',
+                                  side_effect=_fake_run):
+            os_testr.main()
+
+    def test_pdb(self):
+        namespace = os_testr.get_parser(['--pdb', 'project.tests.foo'])
+
+        def _fake_exit(arg):
+            self.assertTrue(arg)
+
+        def _fake_run(*args, **kwargs):
+            return 'project.tests.foo' in args
+
+        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
+                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
+                mock.patch.object(os_testr,
+                                  'call_subunit_run',
+                                  side_effect=_fake_run):
+            os_testr.main()
+
+    def test_pdb_path(self):
+        namespace = os_testr.get_parser(['--pdb', 'project/tests/foo'])
+
+        def _fake_exit(arg):
+            self.assertTrue(arg)
+
+        def _fake_run(*args, **kwargs):
+            return 'project.tests.foo' in args
+
+        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
+                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
+                mock.patch.object(os_testr,
+                                  'call_subunit_run',
+                                  side_effect=_fake_run):
+            os_testr.main()
diff --git a/os_testr/tests/test_os_testr.py b/os_testr/tests/test_regex_builder.py
similarity index 65%
rename from os_testr/tests/test_os_testr.py
rename to os_testr/tests/test_regex_builder.py
index 4fea945..e284036 100644
--- a/os_testr/tests/test_os_testr.py
+++ b/os_testr/tests/test_regex_builder.py
@@ -12,17 +12,11 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-"""
-test_os_testr
-----------------------------------
-
-Tests for `os_testr` module.
-"""
-
 import mock
+
 import six
 
-from os_testr import os_testr
+from os_testr import regex_builder as os_testr
 from os_testr.tests import base
 
 
@@ -35,98 +29,6 @@ class TestPathToRegex(base.TestCase):
         self.assertEqual("openstack.tests.network.v2", result)
 
 
-class TestGetParser(base.TestCase):
-    def test_pretty(self):
-        namespace = os_testr.get_parser(['--pretty'])
-        self.assertEqual(True, namespace[0].pretty)
-        namespace = os_testr.get_parser(['--no-pretty'])
-        self.assertEqual(False, namespace[0].pretty)
-        self.assertRaises(SystemExit, os_testr.get_parser,
-                          ['--no-pretty', '--pretty'])
-
-    def test_slowest(self):
-        namespace = os_testr.get_parser(['--slowest'])
-        self.assertEqual(True, namespace[0].slowest)
-        namespace = os_testr.get_parser(['--no-slowest'])
-        self.assertEqual(False, namespace[0].slowest)
-        self.assertRaises(SystemExit, os_testr.get_parser,
-                          ['--no-slowest', '--slowest'])
-
-    def test_parallel(self):
-        namespace = os_testr.get_parser(['--parallel'])
-        self.assertEqual(True, namespace[0].parallel)
-        namespace = os_testr.get_parser(['--serial'])
-        self.assertEqual(False, namespace[0].parallel)
-        self.assertRaises(SystemExit, os_testr.get_parser,
-                          ['--parallel', '--serial'])
-
-
-class TestCallers(base.TestCase):
-    def test_no_discover(self):
-        namespace = os_testr.get_parser(['-n', 'project.tests.foo'])
-
-        def _fake_exit(arg):
-            self.assertTrue(arg)
-
-        def _fake_run(*args, **kwargs):
-            return 'project.tests.foo' in args
-
-        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
-                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
-                mock.patch.object(os_testr,
-                                  'call_subunit_run',
-                                  side_effect=_fake_run):
-            os_testr.main()
-
-    def test_no_discover_path(self):
-        namespace = os_testr.get_parser(['-n', 'project/tests/foo'])
-
-        def _fake_exit(arg):
-            self.assertTrue(arg)
-
-        def _fake_run(*args, **kwargs):
-            return 'project.tests.foo' in args
-
-        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
-                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
-                mock.patch.object(os_testr,
-                                  'call_subunit_run',
-                                  side_effect=_fake_run):
-            os_testr.main()
-
-    def test_pdb(self):
-        namespace = os_testr.get_parser(['--pdb', 'project.tests.foo'])
-
-        def _fake_exit(arg):
-            self.assertTrue(arg)
-
-        def _fake_run(*args, **kwargs):
-            return 'project.tests.foo' in args
-
-        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
-                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
-                mock.patch.object(os_testr,
-                                  'call_subunit_run',
-                                  side_effect=_fake_run):
-            os_testr.main()
-
-    def test_pdb_path(self):
-        namespace = os_testr.get_parser(['--pdb', 'project/tests/foo'])
-
-        def _fake_exit(arg):
-            self.assertTrue(arg)
-
-        def _fake_run(*args, **kwargs):
-            return 'project.tests.foo' in args
-
-        with mock.patch.object(os_testr, 'exit', side_effect=_fake_exit), \
-                mock.patch.object(os_testr, 'get_parser', return_value=namespace), \
-                mock.patch.object(os_testr,
-                                  'call_subunit_run',
-                                  side_effect=_fake_run):
-            os_testr.main()
-
-
 class TestConstructRegex(base.TestCase):
     def test_regex_passthrough(self):
         result = os_testr.construct_regex(None, None, 'fake_regex', False)
diff --git a/setup.cfg b/setup.cfg
index 409a9f2..27f9ced 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -25,7 +25,7 @@ packages =
 [entry_points]
 console_scripts =
     subunit-trace = os_testr.subunit_trace:main
-    ostestr = os_testr.os_testr:main
+    ostestr = os_testr.ostestr:main
     subunit2html = os_testr.subunit2html:main
     generate-subunit = os_testr.generate_subunit:main