diff --git a/src/solver/optimisation/opt_decompte_variables_et_contraintes.cpp b/src/solver/optimisation/opt_decompte_variables_et_contraintes.cpp
index d68868d347..17738e7b1d 100644
--- a/src/solver/optimisation/opt_decompte_variables_et_contraintes.cpp
+++ b/src/solver/optimisation/opt_decompte_variables_et_contraintes.cpp
@@ -214,7 +214,8 @@ int OPT_DecompteDesVariablesEtDesContraintesDuProblemeAOptimiser(PROBLEME_HEBDO*
         }
         if (!Pump && !TurbEntreBornes && MonitorHourlyLev)
         {
-            throw FatalError("Level explicit modeling requires flexible generation");
+            const std::string areaName(problemeHebdo->NomsDesPays[pays]);
+            throw FatalError("Level explicit modeling requires flexible generation in area " + areaName);
         }
     }