diff --git a/dingo/MetabolicNetwork.py b/dingo/MetabolicNetwork.py
index 738aa730..3d63094b 100644
--- a/dingo/MetabolicNetwork.py
+++ b/dingo/MetabolicNetwork.py
@@ -332,6 +332,8 @@ def set_active_bound(reaction: str, reac_index: int, bound: float) -> None:
             set_active_bound(
                 rxn_id, reac_index, min(0.0, -self._lb[reac_index] if is_export else self._ub[reac_index])
             )
+        self._medium = medium
+        self._opt_vector = None
 
     @reactions_map.setter
     def reactions_map(self, value):