diff --git a/trytond/trytond/ir/queue_.py b/trytond/trytond/ir/queue_.py
index 2b9a52227c..e3044e570a 100644
--- a/trytond/trytond/ir/queue_.py
+++ b/trytond/trytond/ir/queue_.py
@@ -140,7 +140,7 @@ class Queue(ModelSQL):
                 seconds, = row
 
         if not task_id and database.has_channel():
-            cursor.execute('LISTEN "%s"', (cls.__name__,))
+            cursor.execute('LISTEN "%s"' % cls.__name__)
         return task_id, seconds
 
     def run(self):