diff --git a/lib/galaxy/webapps/galaxy/api/datasets.py b/lib/galaxy/webapps/galaxy/api/datasets.py
index a725150c378..74dc747c8b6 100644
--- a/lib/galaxy/webapps/galaxy/api/datasets.py
+++ b/lib/galaxy/webapps/galaxy/api/datasets.py
@@ -374,9 +374,9 @@ class FastAPIDatasets:
         self,
         request: Request,
         history_content_id: HistoryDatasetIDPathParam,
-        history_id: Optional[HistoryIDPathParam] = None,
+        history_id: HistoryIDPathParam | None = None,
         trans=DependsOnTrans,
-        to_ext: Optional[str] = ToExtQueryParam,
+        to_ext: str | None = ToExtQueryParam,
     ):
         """Downloads the whole dataset file. Clients must follow the 302 redirect this route may return."""
         return self._download(request, trans, history_content_id, to_ext)
@@ -396,12 +396,12 @@ class FastAPIDatasets:
         request: Request,
         history_content_id: HistoryDatasetIDPathParam,
         trans=DependsOnTrans,
-        to_ext: Optional[str] = ToExtQueryParam,
+        to_ext: str | None = ToExtQueryParam,
     ):
         """Downloads the whole dataset file. Clients must follow the 302 redirect this route may return."""
         return self._download(request, trans, history_content_id, to_ext)
 
-    def _download(self, request: Request, trans, dataset_id: DecodedDatabaseIdField, to_ext: Optional[str]):
+    def _download(self, request: Request, trans, dataset_id: DecodedDatabaseIdField, to_ext: str | None):
         # Default to_ext to "data" so the route always behaves as a whole-file download (server infers
         # the extension from the datatype) rather than a preview.
         to_ext = to_ext or "data"
diff --git a/lib/galaxy/webapps/galaxy/services/datasets.py b/lib/galaxy/webapps/galaxy/services/datasets.py
index ea2011e4631..d4b1da43ad0 100644
--- a/lib/galaxy/webapps/galaxy/services/datasets.py
+++ b/lib/galaxy/webapps/galaxy/services/datasets.py
@@ -650,9 +650,9 @@ class DatasetsService(ServiceBase, UsesVisualizationMixin):
         self,
         trans: ProvidesHistoryContext,
         dataset_id: DecodedDatabaseIdField,
-        to_ext: Optional[str] = None,
+        to_ext: str | None = None,
         hda_ldda: DatasetSourceType = DatasetSourceType.hda,
-    ) -> Optional[str]:
+    ) -> str | None:
         """Return a backing-store URL a whole-file download can be redirected to, or None to stream.
 
         Used by the dedicated download route; the regular display route never redirects.
@@ -678,7 +678,7 @@ class DatasetsService(ServiceBase, UsesVisualizationMixin):
         self,
         trans: ProvidesHistoryContext,
         dataset_id: DecodedDatabaseIdField,
-        to_ext: Optional[str] = None,
+        to_ext: str | None = None,
         hda_ldda: DatasetSourceType = DatasetSourceType.hda,
     ) -> dict[str, str]:
         """Build response headers for a HEAD download request from object-store metadata.