diff --git a/onnxruntime/core/graph/graph.cc b/onnxruntime/core/graph/graph.cc
index fb34765e59..8c45b4a094 100644
--- a/onnxruntime/core/graph/graph.cc
+++ b/onnxruntime/core/graph/graph.cc
@@ -59,8 +59,7 @@ static void RemoveInvalidValues(ONNX_NAMESPACE::TypeProto& type) {
     for (int i = 0, end = shape->dim_size(); i < end; ++i) {
       auto& dim = *shape->mutable_dim(i);
       if (dim.has_dim_param()) {
-        auto dim_param = dim.dim_param();
-        if (dim_param.empty() || dim_param == "None") {
+        if (dim.dim_param().empty()) {
           dim.clear_dim_param();
         }
       } else if (dim.has_dim_value()) {
diff --git a/onnxruntime/test/python/onnxruntime_test_python.py b/onnxruntime/test/python/onnxruntime_test_python.py
index 4a9deced10..ce4da1a0a6 100644
--- a/onnxruntime/test/python/onnxruntime_test_python.py
+++ b/onnxruntime/test/python/onnxruntime_test_python.py
@@ -114,12 +114,12 @@ class TestInferenceSession(unittest.TestCase):
         self.assertEqual(input_name, "X")
         input_shape = sess.get_inputs()[0].shape
         # Input X has an unknown dimension.
-        self.assertEqual(input_shape, [None, 2])
+        self.assertEqual(input_shape, ['None', 2])
         output_name = sess.get_outputs()[0].name
         self.assertEqual(output_name, "Y")
         output_shape = sess.get_outputs()[0].shape
         # Output X has an unknown dimension.
-        self.assertEqual(output_shape, [None, 1])
+        self.assertEqual(output_shape, ['None', 1])
         res = sess.run([output_name], {input_name: x})
         output_expected = np.array([[5.0], [11.0], [17.0]], dtype=np.float32)
         np.testing.assert_allclose(