diff --git a/tensorflow/tools/api/lib/python_object_to_proto_visitor.py b/tensorflow/tools/api/lib/python_object_to_proto_visitor.py
index 77882d50bae..86994248cc5 100644
--- a/tensorflow/tools/api/lib/python_object_to_proto_visitor.py
+++ b/tensorflow/tools/api/lib/python_object_to_proto_visitor.py
@@ -95,11 +95,13 @@ else:
     return False
 
 
-# Differences created by Generic typing.
+# Differences created by typing implementations.
 _NORMALIZE_TYPE[(
     'tensorflow.python.framework.ops.Tensor')] = (
         "<class 'tensorflow.python.framework.ops.Tensor'>")
 _NORMALIZE_TYPE['typing.Generic'] = "<class 'typing.Generic'>"
+# TODO(mdan): Remove once the golden files are generated in Python 3.7.
+_NORMALIZE_TYPE["<class 'typing._GenericAlias'>"] = 'typing.Union'
 
 
 if sys.version_info.major == 3 and sys.version_info.minor >= 8: