diff --git a/addons/sale_timesheet/models/project_overview.py b/addons/sale_timesheet/models/project_overview.py
index 86a70fd30d2..af275ba9a3b 100644
--- a/addons/sale_timesheet/models/project_overview.py
+++ b/addons/sale_timesheet/models/project_overview.py
@@ -321,7 +321,9 @@ class Project(models.Model):
     def _table_get_empty_so_lines(self):
         """ get the Sale Order Lines having no timesheet but having generated a task or a project """
         so_lines = self.sudo().mapped('sale_line_id.order_id.order_line').filtered(lambda sol: sol.is_service and not sol.is_expense)
-        return set(so_lines.ids), set(so_lines.mapped('order_id').ids)
+        # include the service SO line of SO sharing the same project
+        sale_order = self.env['sale.order'].search([('project_id', 'in', self.ids)])
+        return set(so_lines.ids) | set(sale_order.mapped('order_line').filtered(lambda sol: sol.is_service and not sol.is_expense).ids), set(so_lines.mapped('order_id').ids) | set(sale_order.ids)
 
     # --------------------------------------------------
     # Actions: Stat buttons, ...