diff -r 3be0ff8caea0 Lib/unittest/case.py
--- a/Lib/unittest/case.py	Sun Jun 22 16:44:47 2014 -0400
+++ b/Lib/unittest/case.py	Sat Jun 28 12:14:50 2014 -0400
@@ -119,9 +119,8 @@
     test_item.__unittest_expecting_failure__ = True
     return test_item
 
-
 def testBaseClass(base_class):
-    base_class.__testbase__ = True
+    base_class.__unittest_base_class__ = True
     return base_class
 
 
diff -r 3be0ff8caea0 Lib/unittest/loader.py
--- a/Lib/unittest/loader.py	Sun Jun 22 16:44:47 2014 -0400
+++ b/Lib/unittest/loader.py	Sat Jun 28 12:14:50 2014 -0400
@@ -64,7 +64,7 @@
             raise TypeError("Test cases should not be derived from "
                             "TestSuite. Maybe you meant to derive from "
                             "TestCase?")
-        if testCaseClass.__dict__.get('__testbase__', False):
+        if testCaseClass.__dict__.get('__unittest_base_class__', False):
             raise TypeError("Base test class should not be run.")
 
         testCaseNames = self.getTestCaseNames(testCaseClass)
@@ -79,7 +79,9 @@
         for name in dir(module):
             obj = getattr(module, name)
 
-            if isinstance(obj, type) and issubclass(obj, case.TestCase) and not obj.__dict__.get('__testbase__', False):
+            if isinstance(obj, type) and \
+               issubclass(obj, case.TestCase) and \
+               (not obj.__dict__.get('__unittest_base_class__', False)):
                 tests.append(self.loadTestsFromTestCase(obj))
 
         load_tests = getattr(module, 'load_tests', None)
diff -r 3be0ff8caea0 Lib/unittest/test/baseclassdecorator.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/unittest/test/baseclassdecorator.py	Sat Jun 28 12:14:50 2014 -0400
@@ -0,0 +1,20 @@
+import unittest
+
+@unittest.testBaseClass
+class TestBaseDecoratorBase(unittest.TestCase):
+    def setUp(self):
+        self.is_base_class = True
+            
+    def test_base_class_should_not_run(self):
+        """
+        This test will fail if run by the base class but will pass
+        if run by the child class.
+        """
+        self.assertFalse(self.is_base_class)
+        
+class TestBaseDecoratorChild(TestBaseDecoratorBase):
+    def setUp(self):
+        self.is_base_class = False
+
+if __name__ == "__main__":
+    unittest.main()
diff -r 3be0ff8caea0 Lib/unittest/test/test_case.py
--- a/Lib/unittest/test/test_case.py	Sun Jun 22 16:44:47 2014 -0400
+++ b/Lib/unittest/test/test_case.py	Sat Jun 28 12:14:50 2014 -0400
@@ -1571,12 +1571,12 @@
 
     def test_base_class_should_not_run(self):
         # Issue #14534: Add method to mark unittest.TestCases as "do not run"
-        import unittest.test.testmock.baseclassdecorator
+        from unittest.test import baseclassdecorator
 
         result = unittest.TestResult()
         
         loader = unittest.TestLoader() 
-        suite = loader.loadTestsFromModule(unittest.test.testmock.baseclassdecorator)
+        suite = loader.loadTestsFromModule(baseclassdecorator)
 
         suite.run(result)
         self.assertEqual(result.testsRun, 1)
diff -r 3be0ff8caea0 Lib/unittest/test/testmock/baseclassdecorator.py
--- a/Lib/unittest/test/testmock/baseclassdecorator.py	Sun Jun 22 16:44:47 2014 -0400
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,20 +0,0 @@
-import unittest
-
-@unittest.testBaseClass
-class TestBaseDecoratorBase(unittest.TestCase):
-    def setUp(self):
-        self.is_base_class = True
-            
-    def test_base_class_should_not_run(self):
-        """
-        This test will fail if run by the base class but will pass
-        if run by the child class.
-        """
-        self.assertFalse(self.is_base_class)
-        
-class TestBaseDecoratorChild(TestBaseDecoratorBase):
-    def setUp(self):
-        self.is_base_class = False
-
-if __name__ == "__main__":
-    unittest.main()