Type in docstring.
diff --git a/Lib/doctest.py b/Lib/doctest.py
index fca2f98..74714c5 100644
--- a/Lib/doctest.py
+++ b/Lib/doctest.py
@@ -2135,7 +2135,7 @@
                  setUp=lambda: None, tearDown=lambda: None,
                  checker=None):
     """
-    Convert doctest tests for a mudule to a unittest test suite.
+    Convert doctest tests for a module to a unittest test suite.
 
     This converts each documentation string in a module that
     contains doctest tests to a unittest test case.  If any of the