diff --git a/modules/production_work_timesheet/tryton.cfg b/modules/production_work_timesheet/tryton.cfg
index 341616d566..b70039ea12 100644
--- a/modules/production_work_timesheet/tryton.cfg
+++ b/modules/production_work_timesheet/tryton.cfg
@@ -20,3 +20,4 @@ model:
 [register timesheet_cost]
 model:
     work.WorkCenter
+    work.Work_TimesheetCost
diff --git a/modules/production_work_timesheet/work.py b/modules/production_work_timesheet/work.py
index 755c8f253c..3c2ef8d083 100644
--- a/modules/production_work_timesheet/work.py
+++ b/modules/production_work_timesheet/work.py
@@ -130,6 +130,10 @@ class Work(metaclass=PoolMeta):
                     'timesheet_end_date': date,
                     })
 
+
+class Work_TimesheetCost(metaclass=PoolMeta):
+    __name__ = 'production.work'
+
     @classmethod
     def _get_cost(cls, works):
         pool = Pool()