diff --git a/src/Solver/Mage.py b/src/Solver/Mage.py
index 6ed03e66016cf0ae9573b99b7eb11149ac180bad..1cad3f684e0b5fac5dcb527240fb19dcbc355796 100644
--- a/src/Solver/Mage.py
+++ b/src/Solver/Mage.py
@@ -503,6 +503,9 @@ class Mage8(Mage):
                 if name in ["command_line_arguments"]:
                     continue
 
+                if name is "mage_compute_reach_volume_balance":
+                    value = "O" if value == "y" else "N"
+
                 f.write(f"{name} {value}\n")
 
         return files