diff --git a/Lib/doctest.py b/Lib/doctest.py
index d237811..cb29fcb 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -196,7 +196,7 @@
     """
     if inspect.ismodule(module):
         return module
-    elif isinstance(module, (str, str)):
+    elif isinstance(module, str):
         return __import__(module, globals(), locals(), ["*"])
     elif module is None:
         return sys.modules[sys._getframe(depth).f_globals['__name__']]