diff --git a/spinn_utilities/ranged/ranged_list.py b/spinn_utilities/ranged/ranged_list.py
index 62eb3435..32b01d5f 100644
--- a/spinn_utilities/ranged/ranged_list.py
+++ b/spinn_utilities/ranged/ranged_list.py
@@ -508,6 +508,7 @@ def set_value_by_slice(
 
     def _set_values_list(self, ids: IdsType, value: _ListType) -> None:
         values = self.as_list(value=value, size=len(ids), ids=ids)
+        val: T
         for id_value, val in zip(ids, values):
             self.set_value_by_id(id_value, val)