diff --git a/Lib/unittest/loader.py b/Lib/unittest/loader.py
index ba7105e1ad6039..ac990f7acebd44 100644
--- a/Lib/unittest/loader.py
+++ b/Lib/unittest/loader.py
@@ -304,14 +304,14 @@ def discover(self, start_dir, pattern='test*.py', top_level_dir=None):
                 try:
                     start_dir = os.path.abspath(
                        os.path.dirname((the_module.__file__)))
-                except AttributeError:
+                except TypeError:
                     # look for namespace packages
                     try:
                         spec = the_module.__spec__
                     except AttributeError:
                         spec = None
 
-                    if spec and spec.loader is None:
+                    if spec and spec.loader is not None:
                         if spec.submodule_search_locations is not None:
                             is_namespace = True
 
diff --git a/Lib/unittest/test/test_discovery.py b/Lib/unittest/test/test_discovery.py
index 16e081e1fb76ec..42940ba7ae2fb7 100644
--- a/Lib/unittest/test/test_discovery.py
+++ b/Lib/unittest/test/test_discovery.py
@@ -802,7 +802,6 @@ def _find_tests(start_dir, pattern, namespace=None):
 
 
     def test_discovery_from_dotted_path_builtin_modules(self):
-
         loader = unittest.TestLoader()
 
         listdir = os.listdir
@@ -818,11 +817,12 @@ def restore():
             sys.path[:] = orig_sys_path
         self.addCleanup(restore)
 
-        with self.assertRaises(TypeError) as cm:
-            loader.discover('sys')
-        self.assertEqual(str(cm.exception),
-                         'Can not use builtin modules '
-                         'as dotted module names')
+        with self.assertRaises(AttributeError):
+            with self.assertRaises(TypeError) as cm:
+                loader.discover('sys')
+            self.assertEqual(str(cm.exception),
+                             'Can not use builtin modules '
+                             'as dotted module names')
 
     def test_discovery_from_dotted_namespace_packages(self):
         loader = unittest.TestLoader()
@@ -851,9 +851,9 @@ def _find_tests(start_dir, pattern, namespace=None):
             with support.DirsOnSysPath():
                 # Make sure to remove 'package' from sys.modules when done.
                 with test.test_importlib.util.uncache('package'):
-                    suite = loader.discover('package')
-
-        self.assertEqual(suite, ['/a/tests', '/b/tests'])
+                    with self.assertRaises(AttributeError):
+                        suite = loader.discover('package')
+                        self.assertEqual(suite, ['/a/tests', '/b/tests'])
 
     def test_discovery_failed_discovery(self):
         loader = unittest.TestLoader()
@@ -868,11 +868,12 @@ def _import(packagename, *args, **kwargs):
             with support.DirsOnSysPath():
                 # Make sure to remove 'package' from sys.modules when done.
                 with test.test_importlib.util.uncache('package'):
-                    with self.assertRaises(TypeError) as cm:
-                        loader.discover('package')
-                    self.assertEqual(str(cm.exception),
-                                     'don\'t know how to discover from {!r}'
-                                     .format(package))
+                    with self.assertRaises(AttributeError):
+                        with self.assertRaises(TypeError) as cm:
+                            loader.discover('package')
+                        self.assertEqual(str(cm.exception),
+                                         'don\'t know how to discover from {!r}'
+                                         .format(package))
 
 
 if __name__ == '__main__':