diff --git a/modules/purchase_trade/fee.py b/modules/purchase_trade/fee.py
index 4b13c7c..89daccd 100755
--- a/modules/purchase_trade/fee.py
+++ b/modules/purchase_trade/fee.py
@@ -66,7 +66,7 @@ class Fee(ModelSQL,ModelView):
     quantity = fields.Numeric("Qt",digits='unit',states={'readonly': (Eval('mode') != 'ppack') | Bool(Eval('auto_calculation'))})
     unit = fields.Many2One('product.uom',"Unit",domain=[
             If(Eval('mode') == 'ppack',
-                ('category', '=', Eval('packing_category')),
+                ('category', '=', 8),
                 ()),
             ],
         states={