fastapi
diff --git a/‎fastapi/datastructures.py‎
Lines changed: 5 additions & 0 deletions b/‎fastapi/datastructures.py‎
Lines changed: 5 additions & 0 deletions
diff --git a/‎fastapi/openapi/utils.py‎
Lines changed: 3 additions & 4 deletions b/‎fastapi/openapi/utils.py‎
Lines changed: 3 additions & 4 deletions
@@ -179,3 +179,8 @@ def Default(value: DefaultType) -> DefaultType:
     if the overridden default value was truthy.
     """
     return DefaultPlaceholder(value)  # type: ignore
+
+
+# Sentinel for "parameter not provided" in Param/FieldInfo.
+# Typed as None to satisfy ty
+_Unset = Default(None)
@@ -8,14 +8,13 @@
 from fastapi import routing
 from fastapi._compat import (
     ModelField,
-    Undefined,
     get_definitions,
     get_flat_models_from_fields,
     get_model_name_map,
     get_schema_from_model_field,
     lenient_issubclass,
 )
-from fastapi.datastructures import DefaultPlaceholder
+from fastapi.datastructures import DefaultPlaceholder, _Unset
 from fastapi.dependencies.models import Dependant
 from fastapi.dependencies.utils import (
     _get_flat_fields_from_params,
@@ -170,7 +169,7 @@ def _get_openapi_operation_parameters(
             example = getattr(field_info, "example", None)
             if openapi_examples:
                 parameter["examples"] = jsonable_encoder(openapi_examples)
-            elif example != Undefined:
+            elif example is not _Unset:
                 parameter["example"] = jsonable_encoder(example)
             if getattr(field_info, "deprecated", None):
                 parameter["deprecated"] = True
@@ -207,7 +206,7 @@ def get_openapi_operation_request_body(
         request_media_content["examples"] = jsonable_encoder(
             field_info.openapi_examples
         )
-    elif field_info.example != Undefined:
+    elif field_info.example is not _Unset:
         request_media_content["example"] = jsonable_encoder(field_info.example)
     request_body_oai["content"] = {request_media_type: request_media_content}
     return request_body_oai