diff --git a/production.py b/production.py
index cac1deb..1a602cc 100644
--- a/production.py
+++ b/production.py
@@ -107,7 +107,7 @@ class Task(ModelSQL, ModelView):
             ('create_date', '>=', thirty_minutes_ago)
         ]
         if args.get('sale_id'):
-            dom.append('line.sale', '=', args['sale_id'])
+            dom.append(('line.sale', '=', args['sale_id']))
 
         fields = [
             'name', 'note', 'quantity', 'sale_number',