diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
index bb337f1..227879c 100644
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -245,7 +245,7 @@
     # objects used in assert methods) will be printed on failure in *addition*
     # to any explicit message passed.
 
-    longMessage = False
+    longMessage = True
 
     # This attribute sets the maximum length of a diff in failure messages
     # by assert methods using difflib. It is looked up as an instance attribute
diff --git a/Lib/unittest/test/test_assertions.py b/Lib/unittest/test/test_assertions.py
index 0ee7edb..69572ee 100644
--- a/Lib/unittest/test/test_assertions.py
+++ b/Lib/unittest/test/test_assertions.py
@@ -127,7 +127,7 @@
         self.testableFalse = TestableTestFalse('testTest')
 
     def testDefault(self):
-        self.assertFalse(unittest.TestCase.longMessage)
+        self.assertTrue(unittest.TestCase.longMessage)
 
     def test_formatMsg(self):
         self.assertEqual(self.testableFalse._formatMessage(None, "foo"), "foo")