diff --git a/addons/mrp/models/mrp_workcenter.py b/addons/mrp/models/mrp_workcenter.py
index 5f1e347a062..a47697478dc 100644
--- a/addons/mrp/models/mrp_workcenter.py
+++ b/addons/mrp/models/mrp_workcenter.py
@@ -418,7 +418,7 @@ class MrpWorkcenterProductivity(models.Model):
 
     @api.onchange('duration')
     def _duration_changed(self):
-        self.date_end = self.date_start + timedelta(minutes=self.duration)
+        self.date_start = self.date_end - timedelta(minutes=self.duration)
         self._loss_type_change()
 
     @api.onchange('date_start')