diff -r 8e180b2067e4 Lib/doctest.py
--- a/Lib/doctest.py	Mon Sep 30 22:29:48 2013 +0200
+++ b/Lib/doctest.py	Tue Oct 01 11:37:38 2013 -0400
@@ -1324,8 +1324,8 @@
 
                 # Another chance if they didn't care about the detail.
                 elif self.optionflags & IGNORE_EXCEPTION_DETAIL:
-                    m1 = re.match(r'(?:[^:]*\.)?([^:]*:)', example.exc_msg)
-                    m2 = re.match(r'(?:[^:]*\.)?([^:]*:)', exc_msg)
+                    m1 = re.match(r'(?:[^:]*\.)?([^:]*:?)', example.exc_msg)
+                    m2 = re.match(r'(?:[^:]*\.)?([^:]*:?)', exc_msg)
                     if m1 and m2 and check(m1.group(1), m2.group(1),
                                            self.optionflags):
                         outcome = SUCCESS
diff -r 8e180b2067e4 Lib/test/test_doctest.py
--- a/Lib/test/test_doctest.py	Mon Sep 30 22:29:48 2013 +0200
+++ b/Lib/test/test_doctest.py	Tue Oct 01 11:37:38 2013 -0400
@@ -1020,6 +1020,20 @@
         ValueError: message
     TestResults(failed=1, attempted=1)
 
+If the exception does not have a message, you can still use
+IGNORE_EXCEPTION_DETAIL to normalize the modules between Python 2 and 3.
+
+    >>> def f(x):
+    ...     r'''
+    ...     >>> from http.client import HTTPException
+    ...     >>> raise HTTPException() #doctest: +IGNORE_EXCEPTION_DETAIL
+    ...     Traceback (most recent call last):
+    ...     foo.bar.HTTPException
+    ...     '''
+    >>> test = doctest.DocTestFinder().find(f)[0]
+    >>> doctest.DocTestRunner(verbose=False).run(test)
+    TestResults(failed=0, attempted=2)
+
 If an exception is raised but not expected, then it is reported as an
 unexpected exception: