diff --git a/sdk/python/feast/infra/registry/base_registry.py b/sdk/python/feast/infra/registry/base_registry.py
index 9ee3bbbabc..ab841f609b 100644
--- a/sdk/python/feast/infra/registry/base_registry.py
+++ b/sdk/python/feast/infra/registry/base_registry.py
@@ -665,7 +665,7 @@ def to_dict(self, project: str) -> Dict[str, List[Any]]:
 
             odfv_dict["spec"]["userDefinedFunction"][
                 "body"
-            ] = on_demand_feature_view.transformation.udf_string
+            ] = on_demand_feature_view.transformation.udf_string  # type: ignore
             registry_dict["onDemandFeatureViews"].append(odfv_dict)
         for request_feature_view in sorted(
             self.list_request_feature_views(project=project),
diff --git a/sdk/python/feast/on_demand_feature_view.py b/sdk/python/feast/on_demand_feature_view.py
index 69c4bb938f..3c16046a29 100644
--- a/sdk/python/feast/on_demand_feature_view.py
+++ b/sdk/python/feast/on_demand_feature_view.py
@@ -62,7 +62,7 @@ class OnDemandFeatureView(BaseFeatureView):
     features: List[Field]
     source_feature_view_projections: Dict[str, FeatureViewProjection]
     source_request_sources: Dict[str, RequestSource]
-    transformation: Union[OnDemandPandasTransformation]
+    transformation: Union[OnDemandPandasTransformation, OnDemandSubstraitTransformation]
     description: str
     tags: Dict[str, str]
     owner: str
@@ -82,7 +82,9 @@ def __init__(  # noqa: C901
         ],
         udf: Optional[FunctionType] = None,
         udf_string: str = "",
-        transformation: Optional[Union[OnDemandPandasTransformation, OnDemandSubstraitTransformation]] = None,
+        transformation: Optional[
+            Union[OnDemandPandasTransformation, OnDemandSubstraitTransformation]
+        ] = None,
         description: str = "",
         tags: Optional[Dict[str, str]] = None,
         owner: str = "",