diff --git a/models/mutual_guarantee_fund_line.py b/models/mutual_guarantee_fund_line.py
index 6db1207128fc6a7e72c144904739d432dde55ab6..ef15133a1c87d801165a503de8e0d6f877df5e5a 100644
--- a/models/mutual_guarantee_fund_line.py
+++ b/models/mutual_guarantee_fund_line.py
@@ -57,7 +57,7 @@ class MutualGuaranteeFundLine(models.Model):
             if fmg.type == "subscribe" and fmg.amount <= 0:
                 raise ValidationError("Le montant d'une souscription doit être positif")
             elif fmg.type in ["refund", "guarantee_call", "storing"] and fmg.amount >= 0:
-                raise ValidationError("Le montant d'une souscription doit être négatif")
+                raise ValidationError("Le montant d'un remboursement/appel/réserve doit être strictement négatif")
 
     # ------------------------------------------------------
     # Computed fields / Search Fields