diff --git a/pytype/abstract/_pytd_function.py b/pytype/abstract/_pytd_function.py
index 90200c396..10a4bfac2 100644
--- a/pytype/abstract/_pytd_function.py
+++ b/pytype/abstract/_pytd_function.py
@@ -260,40 +260,57 @@ def compatible_with(new, existing, view):
         name = mutation.name
         values = mutation.value
         if obj.from_annotation:
-          params = obj.get_instance_type_parameter(name)
-          ps = {v for v in params.data if should_check(v)}
-          if ps:
-            filtered_values = self.ctx.program.NewVariable()
-            # check if the container type is being broadened.
-            new = []
-            short_name = name.rsplit(".", 1)[-1]
-            for b in values.bindings:
-              if not should_check(b.data) or b.data in ps:
-                filtered_values.PasteBinding(b)
-                continue
-              new_view = datatypes.AccessTrackingDict.merge(
-                  combined_view, view, {values: b})
-              if not compatible_with(values, ps, new_view):
-                combination = [b]
-                bad_param = b.data.get_instance_type_parameter(short_name)
-                if bad_param in new_view:
-                  combination.append(new_view[bad_param])
-                if not node.HasCombination(combination):
-                  # Since HasCombination is expensive, we don't use it to
-                  # pre-filter bindings, but once we think we have an error, we
-                  # should double-check that the binding is actually visible. We
-                  # also drop non-visible bindings from filtered_values.
-                  continue
-                filtered_values.PasteBinding(b)
-                new.append(b.data)
-            # By updating filtered_mutations only when ps is non-empty, we
-            # filter out mutations to parameters with type Any.
-            filtered_mutations.append(
-                function.Mutation(obj, name, filtered_values))
-            if new:
-              errors[obj][short_name] = (params, values, obj.from_annotation)
+          # We should check for parameter mismatches only if the class is
+          # generic. Consider:
+          #   class A(tuple[int, int]): ...
+          #   class B(tuple): ...
+          # Although pytype computes mutations for tuple.__new__ for both
+          # classes, the second implicitly inherits from tuple[Any, ...], so
+          # there are no restrictions on the container contents.
+          check_params = False
+          for cls in obj.cls.mro:
+            if isinstance(cls, _classes.ParameterizedClass):
+              check_params = True
+              break
+            elif cls.template:
+              break
         else:
+          check_params = False
+        if not check_params:
           filtered_mutations.append(function.Mutation(obj, name, values))
+          continue
+        params = obj.get_instance_type_parameter(name)
+        ps = {v for v in params.data if should_check(v)}
+        if ps:
+          filtered_values = self.ctx.program.NewVariable()
+          # check if the container type is being broadened.
+          new = []
+          short_name = name.rsplit(".", 1)[-1]
+          for b in values.bindings:
+            if not should_check(b.data) or b.data in ps:
+              filtered_values.PasteBinding(b)
+              continue
+            new_view = datatypes.AccessTrackingDict.merge(
+                combined_view, view, {values: b})
+            if not compatible_with(values, ps, new_view):
+              combination = [b]
+              bad_param = b.data.get_instance_type_parameter(short_name)
+              if bad_param in new_view:
+                combination.append(new_view[bad_param])
+              if not node.HasCombination(combination):
+                # Since HasCombination is expensive, we don't use it to
+                # pre-filter bindings, but once we think we have an error, we
+                # should double-check that the binding is actually visible. We
+                # also drop non-visible bindings from filtered_values.
+                continue
+              filtered_values.PasteBinding(b)
+              new.append(b.data)
+          # By updating filtered_mutations only when ps is non-empty, we
+          # filter out mutations to parameters with type Any.
+          filtered_mutations.append(
+              function.Mutation(obj, name, filtered_values))
+          if new:
+            errors[obj][short_name] = (params, values, obj.from_annotation)
 
       all_mutations = filtered_mutations
 
diff --git a/pytype/config.py b/pytype/config.py
index ee2dfbf4b..30b3ee31f 100644
--- a/pytype/config.py
+++ b/pytype/config.py
@@ -242,7 +242,7 @@ def add_options(o, arglist):
     _flag("--overriding-renamed-parameter-count-checks", False,
           "Enable parameter count checks for overriding methods with "
           "renamed arguments."),
-    _flag("--use-enum-overlay", False,
+    _flag("--use-enum-overlay", True,
           "Use the enum overlay for more precise enum checking."),
     _flag("--strict-none-binding", False,
           "Variables initialized as None retain their None binding."),
diff --git a/pytype/overlays/fiddle_overlay.py b/pytype/overlays/fiddle_overlay.py
index 065d232a7..e38415266 100644
--- a/pytype/overlays/fiddle_overlay.py
+++ b/pytype/overlays/fiddle_overlay.py
@@ -24,6 +24,14 @@
 _INSTANCE_CACHE: Dict[Tuple[Node, abstract.Class, str], abstract.Instance] = {}
 
 
+_CLASS_ALIASES = {
+    "Config": "Config",
+    "PaxConfig": "Config",
+    "Partial": "Partial",
+    "PaxPartial": "Partial"
+}
+
+
 class FiddleOverlay(overlay.Overlay):
   """A custom overlay for the 'fiddle' module."""
 
@@ -61,7 +69,7 @@ def __init__(self, name, ctx, module):
     mixin.HasSlots.init_mixin(self)
     self.set_native_slot("__getitem__", self.getitem_slot)
     # For consistency with the rest of the overlay
-    self.fiddle_type_name = name
+    self.fiddle_type_name = _CLASS_ALIASES[name]
     self.module = module
 
   def __repr__(self):
@@ -150,7 +158,9 @@ def getitem_slot(self, node, index_var) -> Tuple[Node, abstract.Instance]:
     """Specialize the generic class with the value of index_var."""
 
     underlying = index_var.data[0]
-    ret = BuildableType(self.name, underlying, self.ctx, module=self.module)
+    ret = BuildableType(
+        self.fiddle_type_name, underlying, self.ctx, module=self.module
+    )
     return node, ret.to_variable(node)
 
   def get_own_new(self, node, value) -> Tuple[Node, Variable]:
@@ -177,12 +187,16 @@ def __init__(
     super().__init__(base_cls, formal_type_parameters, ctx, template)  # pytype: disable=wrong-arg-types
     self.fiddle_type_name = fiddle_type_name
     self.underlying = underlying
+    self.module = module
 
   def replace(self, inner_types):
     inner_types = dict(inner_types)
     new_underlying = inner_types[abstract_utils.T]
     typ = self.__class__
-    return typ(self.fiddle_type_name, new_underlying, self.ctx, self.template)
+    return typ(
+        self.fiddle_type_name, new_underlying, self.ctx, self.template,
+        self.module
+    )
 
   def instantiate(self, node, container=None):
     _, ret = make_instance(
@@ -244,6 +258,7 @@ def make_instance(
 ) -> Tuple[Node, abstract.BaseValue]:
   """Generate a Buildable instance from an underlying template class."""
 
+  subclass_name = _CLASS_ALIASES[subclass_name]
   if subclass_name not in ("Config", "Partial"):
     raise ValueError(f"Unexpected instance class: {subclass_name}")
 
diff --git a/pytype/pyi/definitions.py b/pytype/pyi/definitions.py
index f605fc0fd..7e01cd238 100644
--- a/pytype/pyi/definitions.py
+++ b/pytype/pyi/definitions.py
@@ -173,6 +173,10 @@ def _convert_annotated(x):
   """Convert everything to a string to store it in pytd.Annotated."""
   if isinstance(x, types.Pyval):
     return x.repr_str()
+  # TODO(rechen): ast.unparse is new in Python 3.9, so we can drop the hasattr
+  # check once pytype stops supporting 3.8.
+  elif isinstance(x, astlib.AST) and hasattr(astlib, "unparse"):
+    return astlib.unparse(x)
   elif isinstance(x, dict):
     return metadata.to_string(x)
   elif isinstance(x, tuple):
diff --git a/pytype/pyi/parser_test.py b/pytype/pyi/parser_test.py
index 7a3e4a3f2..3cb5674f4 100644
--- a/pytype/pyi/parser_test.py
+++ b/pytype/pyi/parser_test.py
@@ -6,6 +6,7 @@
 from pytype.pyi import parser_test_base
 from pytype.pytd import pytd
 from pytype.tests import test_base
+from pytype.tests import test_utils
 
 import unittest
 
@@ -2846,6 +2847,20 @@ class Foo:
           y: Annotated[int, {'tag': 'call', 'fn': 'unit', 'posargs': ('s',), 'kwargs': {'exp': 9}}]
     """)
 
+  @test_utils.skipBeforePy((3, 9), "requires ast.unparse, new in 3.9")
+  def test_name(self):
+    self.check("""
+      from typing_extensions import Annotated
+
+      class Foo:
+          x: Annotated[int, Signal]
+    """, """
+      from typing_extensions import Annotated
+
+      class Foo:
+          x: Annotated[int, Signal]
+    """)
+
 
 class ErrorTest(test_base.UnitTest):
   """Test parser errors."""
diff --git a/pytype/pytd/printer.py b/pytype/pytd/printer.py
index 492c30990..204b77da5 100644
--- a/pytype/pytd/printer.py
+++ b/pytype/pytd/printer.py
@@ -723,7 +723,7 @@ def VisitGenericType(self, node):
         assert isinstance(param, (pytd.NothingType, pytd.TypeParameter)), param
       parameters = ("...",) + parameters[1:]
     return (self.MaybeCapitalize(node.base_type) +
-            "[" + ", ".join(parameters) + "]")
+            "[" + ", ".join(str(p) for p in parameters) + "]")
 
   def VisitCallableType(self, node):
     typ = self.MaybeCapitalize(node.base_type)
diff --git a/pytype/tests/test_test_code.py b/pytype/tests/test_test_code.py
index 894816712..6880f1d14 100644
--- a/pytype/tests/test_test_code.py
+++ b/pytype/tests/test_test_code.py
@@ -142,6 +142,22 @@ def test_bar(self):
           other_mock.return_value.__enter__ = lambda x: x
     """)
 
+  def test_decorated_setup(self):
+    self.Check("""
+      from typing import Any
+      import unittest
+      from unittest import mock
+
+      random_module: Any
+
+      class FooTest(unittest.TestCase):
+        @mock.patch.object(random_module, 'attr')
+        def setUp(self):
+          self.x = 42
+        def test_something(self):
+          assert_type(self.x, int)
+    """)
+
 
 if __name__ == "__main__":
   test_base.main()
diff --git a/pytype/tests/test_tuple2.py b/pytype/tests/test_tuple2.py
index 37b841733..e0e39ee6b 100644
--- a/pytype/tests/test_tuple2.py
+++ b/pytype/tests/test_tuple2.py
@@ -253,6 +253,33 @@ def f(x: tuple[int, int]):
       f((0, 0))  # ok
     """)
 
+  def test_imported_tuple_subclass_with_new(self):
+    with self.DepTree([("foo.pyi", """
+      from typing import TypeVar
+      _T = TypeVar('_T', bound=C)
+      class C(tuple):
+        def __new__(
+            cls: type[_T], x: str | list[tuple[int, tuple[int, int]]]
+        ) -> _T: ...
+    """)]):
+      ty = self.Infer("""
+        import foo
+        class A:
+          def __init__(self, c: foo.C):
+            self.c = foo.C('+'.join([f'{x}{y}' for x, y in c]))
+        class B:
+          def __init__(self, c: foo.C = foo.C([(0, (1, 2))])):
+            pass
+      """)
+      self.assertTypesMatchPytd(ty, """
+        import foo
+        class A:
+          c: foo.C
+          def __init__(self, c: foo.C) -> None: ...
+        class B:
+          def __init__(self, c: foo.C = ...) -> None: ...
+      """)
+
 
 if __name__ == "__main__":
   test_base.main()
diff --git a/pytype/tools/analyze_project/pytype_runner_test.py b/pytype/tools/analyze_project/pytype_runner_test.py
index 3c7f5e9f5..e21b21dbe 100644
--- a/pytype/tools/analyze_project/pytype_runner_test.py
+++ b/pytype/tools/analyze_project/pytype_runner_test.py
@@ -232,7 +232,7 @@ def setUp(self):
   def assertFlags(self, flags, expected_flags):
     # Add temporary flags that are set to true by default here, so that they are
     # filtered out of tests.
-    temporary_flags = set()
+    temporary_flags = {'--use-enum-overlay'}
     self.assertEqual(flags - temporary_flags, expected_flags)
 
   # --disable tests a flag with a string value.
diff --git a/pytype/tracer_vm.py b/pytype/tracer_vm.py
index 304a4fd57..f8791a641 100644
--- a/pytype/tracer_vm.py
+++ b/pytype/tracer_vm.py
@@ -401,7 +401,8 @@ def bind(cur_node, m):
     cls = valself.data.cls
     bound_method = bind(node, method) if obj == cls else method
     if (not isinstance(cls, abstract.InterpreterClass) or
-        any(isinstance(m, abstract.FUNCTION_TYPES) for m in bound_method.data)):
+        any(isinstance(m, abstract.INTERPRETER_FUNCTION_TYPES)
+            for m in bound_method.data)):
       return node, bound_method
     # If the method is not something that pytype recognizes as a function -
     # which can happen if the method is decorated, for example - then we look up