diff --git a/src/feedbacks/mod.rs b/src/feedbacks/mod.rs
index f6047643e9..9eca463d21 100644
--- a/src/feedbacks/mod.rs
+++ b/src/feedbacks/mod.rs
@@ -64,3 +64,8 @@ impl<'a, MapT: Integer + Copy + 'static, ReducerT: Reducer<MapT>> MapFeedback<Ma
         }
     }
 }
+
+#[allow(dead_code)]
+type MaxMapFeedback<MapT> = MapFeedback<MapT, dyn MaxReducer<MapT>>;
+#[allow(dead_code)]
+type MinMapFeedback<MapT> = MapFeedback<MapT, dyn MinReducer<MapT>>;