diff --git a/test_onetimepad.py b/test_onetimepad.py
index dfc3079..fd27e97 100644
--- a/test_onetimepad.py
+++ b/test_onetimepad.py
@@ -28,3 +28,7 @@ class TestOneTimePad(unittest.TestCase):
             else:
                 self.assertFalse(bool(len(line)),
                                  'line {0} is empty'.format(lineno))
+
+
+if __name__ == '__main__':
+    unittest.main()