diff -r 815b88454e3e Lib/test/test_importlib/builtin/test_loader.py
--- a/Lib/test/test_importlib/builtin/test_loader.py	Fri Aug 31 17:14:31 2012 -0400
+++ b/Lib/test/test_importlib/builtin/test_loader.py	Sat Sep 01 01:25:03 2012 +0100
@@ -92,7 +92,6 @@
             method = getattr(machinery.BuiltinImporter, meth_name)
         with self.assertRaises(ImportError) as cm:
             method(builtin_util.BAD_NAME)
-        self.assertRaises(builtin_util.BAD_NAME)
 
 
 
diff -r 815b88454e3e Lib/unittest/case.py
--- a/Lib/unittest/case.py	Fri Aug 31 17:14:31 2012 -0400
+++ b/Lib/unittest/case.py	Sat Sep 01 01:25:03 2012 +0100
@@ -567,6 +567,17 @@
                the_exception = cm.exception
                self.assertEqual(the_exception.error_code, 3)
         """
+        def check_is_exception(e):
+            if not type(e) is type or not issubclass(e, BaseException):
+                raise TypeError('assertRaises arg 1 must be an exception type '
+                                'or tuple of exception types')
+
+        if type(excClass) is tuple:
+            for e in excClass:
+                check_is_exception(e)
+        else:
+            check_is_exception(excClass)
+
         context = _AssertRaisesContext(excClass, self, callableObj)
         return context.handle('assertRaises', callableObj, args, kwargs)
 
diff -r 815b88454e3e Lib/unittest/test/test_case.py
--- a/Lib/unittest/test/test_case.py	Fri Aug 31 17:14:31 2012 -0400
+++ b/Lib/unittest/test/test_case.py	Sat Sep 01 01:25:03 2012 +0100
@@ -1027,6 +1027,27 @@
         self.assertIsInstance(e, ExceptionMock)
         self.assertEqual(e.args[0], v)
 
+    def testAssertRaisesNoExceptionType(self):
+        ctx = self.assertRaises(TypeError)
+        with ctx:
+            self.assertRaises(1)
+        self.assertIsInstance(ctx.exception, TypeError)
+
+        ctx = self.assertRaises(TypeError)
+        with ctx:
+            self.assertRaises(object)
+        self.assertIsInstance(ctx.exception, TypeError)
+
+        ctx = self.assertRaises(TypeError)
+        with ctx:
+            self.assertRaises((TypeError, 1))
+        self.assertIsInstance(ctx.exception, TypeError)
+
+        ctx = self.assertRaises(TypeError)
+        with ctx:
+            self.assertRaises((object, 1))
+        self.assertIsInstance(ctx.exception, TypeError)
+
     def testAssertWarnsCallable(self):
         def _runtime_warn():
             warnings.warn("foo", RuntimeWarning)
diff -r 815b88454e3e Misc/ACKS
--- a/Misc/ACKS	Fri Aug 31 17:14:31 2012 -0400
+++ b/Misc/ACKS	Sat Sep 01 01:25:03 2012 +0100
@@ -1102,6 +1102,7 @@
 Frank Visser
 Johannes Vogel
 Sjoerd de Vries
+Daniel Wagner-Hall
 Niki W. Waibel
 Wojtek Walczak
 Charles Waldman