diff --git a/src/py/flwr/server/superlink/linkstate/in_memory_linkstate.py b/src/py/flwr/server/superlink/linkstate/in_memory_linkstate.py
index 42d57b4c0be0..a5b8a12cc9d5 100644
--- a/src/py/flwr/server/superlink/linkstate/in_memory_linkstate.py
+++ b/src/py/flwr/server/superlink/linkstate/in_memory_linkstate.py
@@ -480,7 +480,7 @@ def update_run_status(self, run_id: int, new_status: RunStatus) -> bool:
             run_record.status = new_status
             return True
 
-    def get_pending_run_id(self) -> int | None:
+    def get_pending_run_id(self) -> Optional[int]:
         """Get the `run_id` of a run with `Status.PENDING` status, if any."""
         pending_run_id = None
 
diff --git a/src/py/flwr/server/superlink/linkstate/sqlite_linkstate.py b/src/py/flwr/server/superlink/linkstate/sqlite_linkstate.py
index bf097fa2817f..bcf0b319f307 100644
--- a/src/py/flwr/server/superlink/linkstate/sqlite_linkstate.py
+++ b/src/py/flwr/server/superlink/linkstate/sqlite_linkstate.py
@@ -943,7 +943,7 @@ def update_run_status(self, run_id: int, new_status: RunStatus) -> bool:
         self.query(query % timestamp_fld, data)
         return True
 
-    def get_pending_run_id(self) -> int | None:
+    def get_pending_run_id(self) -> Optional[int]:
         """Get the `run_id` of a run with `Status.PENDING` status, if any."""
         pending_run_id = None