diff --git a/payroll.py b/payroll.py
index 0a6202e..e63d529 100644
--- a/payroll.py
+++ b/payroll.py
@@ -2480,6 +2480,6 @@ class PayrollTask(ModelSQL, ModelView):
         if self.data.get('start_extras') and self.data.get('end_extras'):
             values['start_extras'] = self.data.get('start_extras')
             values['end_extras'] = self.data.get('end_extras')
-        if self.data.get('project'):
-            values['project'] = project
+        if hasattr(contract, 'project') and contract.project:
+            values['project'] = contract.project.id
         return values