diff --git a/Lib/unittest.py b/Lib/unittest.py
index c8943e7..bf7baa1 100644
--- a/Lib/unittest.py
+++ b/Lib/unittest.py
@@ -1640,9 +1640,11 @@
     """
     USAGE = USAGE
     def __init__(self, module='__main__', defaultTest=None,
-                 argv=None, testRunner=TextTestRunner,
+                 argv=None, testRunner=None,
                  testLoader=defaultTestLoader, exit=True,
                  verbosity=1):
+        if testRunner is None:
+            testRunner = TextTestRunner
         if isinstance(module, basestring):
             self.module = __import__(module)
             for part in module.split('.')[1:]: