diff --git a/attached_assets/image_1757348534399.png b/attached_assets/image_1757348534399.png
new file mode 100644
index 0000000..8d01b35
Binary files /dev/null and b/attached_assets/image_1757348534399.png differ
diff --git a/client/src/pages/Avoirs.tsx b/client/src/pages/Avoirs.tsx
index 23d8664..10eab00 100644
--- a/client/src/pages/Avoirs.tsx
+++ b/client/src/pages/Avoirs.tsx
@@ -71,7 +71,10 @@ const avoirSchema = z.object({
   supplierId: z.coerce.number().min(1, "Veuillez sélectionner un fournisseur"),
   groupId: z.coerce.number().min(1, "Veuillez sélectionner un magasin"),
   invoiceReference: z.string().optional(),
-  amount: z.preprocess((val) => val === "" ? undefined : val, z.coerce.number().positive().optional()),
+  amount: z.union([
+    z.string().length(0).transform(() => undefined),
+    z.coerce.number().positive()
+  ]).optional(),
   comment: z.string().optional(),
   commercialProcessed: z.boolean().optional(),
   status: z.enum(["En attente de demande", "Demandé", "Reçu"]).optional(),