diff --git a/client/src/pages/Avoirs.tsx b/client/src/pages/Avoirs.tsx
index a3797fc..6f2b5a8 100644
--- a/client/src/pages/Avoirs.tsx
+++ b/client/src/pages/Avoirs.tsx
@@ -88,7 +88,7 @@ const avoirSchema = z.object({
     })
   ]).optional(),
   comment: z.string().optional(),
-  commercialProcessed: z.boolean().optional(),
+  commercialProcessed: z.boolean().default(false),
   status: z.enum(["En attente de demande", "Demandé", "Reçu"]).optional(),
 });
 
@@ -272,6 +272,11 @@ export default function Avoirs() {
   // Handle edit form submission
   const onEditSubmit = (data: AvoirFormData) => {
     if (selectedAvoir) {
+      console.log('💰 Editing avoir - Form data sent:', {
+        originalCommercial: selectedAvoir.commercialProcessed,
+        formCommercial: data.commercialProcessed,
+        fullData: data
+      });
       editAvoirMutation.mutate({ id: selectedAvoir.id, data });
     }
   };
diff --git a/server/routes.ts b/server/routes.ts
index c096368..05f0cb0 100644
--- a/server/routes.ts
+++ b/server/routes.ts
@@ -2501,10 +2501,19 @@ export async function registerRoutes(app: Express): Promise<Server> {
         }
       }
 
-      const updatedAvoir = await storage.updateAvoir(id, req.body);
+      // ✅ CRITICAL FIX: Validate data with Zod schema (partial)
+      console.log('💰 PUT Avoir - Raw body received:', JSON.stringify(req.body, null, 2));
+      const validatedData = insertAvoirSchema.partial().parse(req.body);
+      console.log('💰 PUT Avoir - Validated data:', JSON.stringify(validatedData, null, 2));
+
+      const updatedAvoir = await storage.updateAvoir(id, validatedData);
       console.log('✅ Avoir updated:', id, 'by user:', user.id);
       res.json(updatedAvoir);
     } catch (error) {
+      if (error instanceof z.ZodError) {
+        console.error('❌ [PUT AVOIR] ERREURS VALIDATION ZOD:', JSON.stringify(error.errors, null, 2));
+        return res.status(400).json({ message: "Validation error", errors: error.errors });
+      }
       console.error("Error updating avoir:", error);
       res.status(500).json({ message: "Failed to update avoir" });
     }