diff --git a/tests/test_utils.py b/tests/test_utils.py
index 3eb552b..5c7a94d 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -7,6 +7,7 @@ import pytest
 
 from pydantic import BaseModel
 from pydantic.color import Color
+from pydantic.fields import Undefined
 from pydantic.typing import display_as_type, is_new_type, new_type_supertype
 from pydantic.utils import ValueItems, deep_update, import_string, lenient_issubclass, truncate
 
@@ -260,3 +261,7 @@ def test_deep_update_is_not_mutating():
     updated_mapping = deep_update(mapping, {'key': {'inner_key': {'other_deep_key': 1}}})
     assert updated_mapping == {'key': {'inner_key': {'deep_key': 1, 'other_deep_key': 1}}}
     assert mapping == {'key': {'inner_key': {'deep_key': 1}}}
+
+
+def test_undefined_repr():
+    assert repr(Undefined) == 'PydanticUndefined'