diff --git a/tensorflow/python/autograph/pyct/common_transformers/anf.py b/tensorflow/python/autograph/pyct/common_transformers/anf.py
index 009ae2b4417..15ceefcbdd4 100644
--- a/tensorflow/python/autograph/pyct/common_transformers/anf.py
+++ b/tensorflow/python/autograph/pyct/common_transformers/anf.py
@@ -36,11 +36,11 @@ from tensorflow.python.autograph.pyct import templates
 from tensorflow.python.autograph.pyct import transformer
 
 
+# TODO(mdan): Replace with naming.Namer.
 class DummyGensym(object):
   """A dumb gensym that suffixes a stem by sequential numbers from 1000."""
 
-  def __init__(self, ctx):
-    del ctx
+  def __init__(self):
     # A proper implementation needs to account for:
     #   * ctx.info.namespace
     #   * all the symbols defined in the AST
@@ -105,14 +105,12 @@ class AnfTransformer(transformer.Base):
   # processing the `body` and the `orelse` need to be kept together with them,
   # and not accidentally lifted out of the `if`.
 
-  def __init__(self, ctx, config, gensym_source=None):
+  def __init__(self, ctx, config):
     """Creates an ANF transformer.
 
     Args:
       ctx: transformer.Context
       config: Configuration
-      gensym_source: An optional object with the same interface as `DummyGensym`
-        for generating unique names
     """
     super(AnfTransformer, self).__init__(ctx)
     if config is None:
@@ -137,10 +135,7 @@ class AnfTransformer(transformer.Base):
           (ASTEdgePattern(ANY, ANY, gast.expr), REPLACE)]
     else:
       self._overrides = config
-    if gensym_source is None:
-      self._gensym = DummyGensym(ctx)
-    else:
-      self._gensym = gensym_source(ctx)
+    self._gensym = DummyGensym()
     self._pending_statements = []
 
   def _consume_pending_statements(self):
@@ -529,7 +524,7 @@ def _is_trivial(node):
   return False
 
 
-def transform(node, ctx, config=None, gensym_source=None):
+def transform(node, ctx, config=None):
   """Converts the given node to A-normal form (ANF).
 
   The general idea of A-normal form: https://en.wikipedia.org/wiki/A-normal_form
@@ -605,7 +600,5 @@ def transform(node, ctx, config=None, gensym_source=None):
       argument provide?
     config: Optional ANF configuration.  If omitted, ANF replaces all expression
       expect literal constants.
-    gensym_source: An optional object with the same interface as `DummyGensym`
-      for generating unique names.
   """
-  return AnfTransformer(ctx, config, gensym_source=gensym_source).visit(node)
+  return AnfTransformer(ctx, config).visit(node)
diff --git a/tensorflow/python/autograph/pyct/common_transformers/anf_test.py b/tensorflow/python/autograph/pyct/common_transformers/anf_test.py
index 80715f115be..ced2ee3a975 100644
--- a/tensorflow/python/autograph/pyct/common_transformers/anf_test.py
+++ b/tensorflow/python/autograph/pyct/common_transformers/anf_test.py
@@ -29,30 +29,8 @@ from tensorflow.python.autograph.pyct.common_transformers import anf
 from tensorflow.python.platform import test
 
 
-class DummyGensym(object):
-  """A dumb gensym that suffixes a stem by sequential numbers from 1000."""
-
-  def __init__(self, ctx):
-    del ctx
-    # A proper implementation needs to account for:
-    #   * ctx.info.namespace
-    #   * all the symbols defined in the AST
-    #   * the symbols generated so far
-    self._idx = 0
-
-  def new_name(self, stem='tmp'):
-    self._idx += 1
-    return stem + '_' + str(1000 + self._idx)
-
-
-# These two test functions have to be top-level, not nested, for compatibility
-# with some unknown version of Python 2.7 preceding 2.7.15.  Why?  Because
-# `exec` and nested function definitions _incompatibly_ change the
-# representation of local variables, such that `exec` inside a nested function
-# definition is a syntax error in that version.  The tuple form of `exec` fixes
-# this problem, but apparently that was introduced in some unknown version of
-# Python that's more recent than at least one version that we wish to be
-# compatible with.
+# TODO(mdan): These two functions no longer need to be at the top level.
+# TODO(mdan): Don't use exec.
 def exec_test_function():
   # The point is to test A-normal form conversion of exec
   # pylint: disable=exec-used
@@ -88,9 +66,7 @@ class AnfTestBase(test.TestCase):
     # statements.
     exp_node, _ = parser.parse_entity(expected_fn, future_features=())
     node, _ = parser.parse_entity(test_fn, future_features=())
-    node = anf.transform(
-        node, self._simple_context(),
-        config=config, gensym_source=DummyGensym)
+    node = anf.transform(node, self._simple_context(), config=config)
     exp_name = exp_node.name
     # Ignoring the function names in the result because they can't be
     # the same (because both functions have to exist in the same scope
@@ -98,8 +74,7 @@ class AnfTestBase(test.TestCase):
     node.name = exp_name
     self.assert_same_ast(exp_node, node)
     # Check that ANF is idempotent
-    node_repeated = anf.transform(
-        node, self._simple_context(), gensym_source=DummyGensym)
+    node_repeated = anf.transform(node, self._simple_context())
     self.assert_same_ast(node_repeated, node)
 
 
@@ -466,9 +441,7 @@ class AnfNonTransformationTest(AnfTransformerTest):
     orig_source = parser.unparse(node, indentation='  ')
     orig_str = textwrap.dedent(orig_source).strip()
     config = [(anf.ANY, anf.LEAVE)]  # Configuration to transform nothing
-    node = anf.transform(
-        node, self._simple_context(),
-        config=config, gensym_source=DummyGensym)
+    node = anf.transform(node, self._simple_context(), config=config)
     new_source = parser.unparse(node, indentation='  ')
     new_str = textwrap.dedent(new_source).strip()
     self.assertEqual(orig_str, new_str)