diff --git a/tempest/tests/cmd/test_run.py b/tempest/tests/cmd/test_run.py
index 7ac347d..6e1250f 100644
--- a/tempest/tests/cmd/test_run.py
+++ b/tempest/tests/cmd/test_run.py
@@ -13,6 +13,7 @@
 # under the License.
 
 import argparse
+import atexit
 import os
 import shutil
 import subprocess
@@ -25,6 +26,7 @@
 from tempest.tests import base
 
 DEVNULL = open(os.devnull, 'wb')
+atexit.register(DEVNULL.close)
 
 
 class TestTempestRun(base.TestCase):
@@ -68,6 +70,34 @@
         self.assertEqual('i_am_a_fun_little_regex',
                          self.run_cmd._build_regex(args))
 
+    def test__build_whitelist_file(self):
+        args = mock.Mock(spec=argparse.Namespace)
+        setattr(args, 'smoke', False)
+        setattr(args, 'regex', None)
+        self.tests = tempfile.NamedTemporaryFile(
+            prefix='whitelist', delete=False)
+        self.tests.write(b"volume \n compute")
+        self.tests.close()
+        setattr(args, 'whitelist_file', self.tests.name)
+        setattr(args, 'blacklist_file', None)
+        self.assertEqual("volume|compute",
+                         self.run_cmd._build_regex(args))
+        os.unlink(self.tests.name)
+
+    def test__build_blacklist_file(self):
+        args = mock.Mock(spec=argparse.Namespace)
+        setattr(args, 'smoke', False)
+        setattr(args, 'regex', None)
+        self.tests = tempfile.NamedTemporaryFile(
+            prefix='blacklist', delete=False)
+        self.tests.write(b"volume \n compute")
+        self.tests.close()
+        setattr(args, 'whitelist_file', None)
+        setattr(args, 'blacklist_file', self.tests.name)
+        self.assertEqual("^((?!compute|volume).)*$",
+                         self.run_cmd._build_regex(args))
+        os.unlink(self.tests.name)
+
 
 class TestRunReturnCode(base.TestCase):
     def setUp(self):