diff --git a/maintenance.py b/maintenance.py
index b530eaa..151e510 100644
--- a/maintenance.py
+++ b/maintenance.py
@@ -369,7 +369,7 @@ class MaintenanceServiceLine(Workflow, ModelSQL, ModelView):
         pool = Pool()
         ConfigurationEquipment = pool.get('optical_equipment.configuration')
         config = ConfigurationEquipment(1)
-        if config.technician_responsible.invima:
+        if config.technician_responsible:
             return config.technician_responsible.invima
 
     @classmethod