diff --git a/src/solver/simulation/sim_calcul_economique.cpp b/src/solver/simulation/sim_calcul_economique.cpp
index e14f85e945..b6984936aa 100644
--- a/src/solver/simulation/sim_calcul_economique.cpp
+++ b/src/solver/simulation/sim_calcul_economique.cpp
@@ -837,6 +837,12 @@ void SIM_RenseignementProblemeHebdo(const Study& study,
                     }
 
                     marginGen = weekGenerationTarget;
+
+                    if (problem.CaracteristiquesHydrauliques[k].NiveauInitialReservoir
+                        < weekTarget_tmp)
+                    {
+                        marginGen = problem.CaracteristiquesHydrauliques[k].NiveauInitialReservoir;
+                    }
                 }
 
                 if (not problem.CaracteristiquesHydrauliques[k].TurbinageEntreBornes)