diff --git a/bemade_fsm/models/task.py b/bemade_fsm/models/task.py
index 3cc7219..296a7c6 100644
--- a/bemade_fsm/models/task.py
+++ b/bemade_fsm/models/task.py
@@ -184,17 +184,21 @@ class Task(models.Model):
                 rec.allow_billable = rec.project_id.allow_billable
 
     def action_fsm_validate(self):
-        visits = self.filtered(lambda t: t.visit_id)
-        non_visits = self - visits
+        # Override to make sure all descendant tasks are validated as well
+        full_hierarchy = self._get_full_hierarchy()
+        visits = self.filtered(lambda t: bool(t.visit_id))
+        non_visits = full_hierarchy - visits
         super(Task, non_visits).action_fsm_validate()
-
         visits._stop_all_timers_and_create_timesheets()
         closed_stage_by_project = visits._get_closed_stage_by_project()
-        super(Task, visits.child_ids).action_fsm_validate()
         for visit in visits:
             stage = closed_stage_by_project[visit.project_id]
             visits.write({'stage_id': stage.id, 'fsm_done': True})
 
+    def _get_full_hierarchy(self):
+        if self.child_ids:
+            return self | self.child_ids._get_full_hierarchy()
+        return self
     def synchronize_name_fsm(self):
         """ Applies naming to the entire task tree for tasks that are part of this
         recordset. Root tasks are named:
diff --git a/bemade_fsm/tests/test_bemade_fsm_common.py b/bemade_fsm/tests/test_bemade_fsm_common.py
index 613db7b..a0fef55 100644
--- a/bemade_fsm/tests/test_bemade_fsm_common.py
+++ b/bemade_fsm/tests/test_bemade_fsm_common.py
@@ -192,3 +192,16 @@ class BemadeFSMBaseTest(TransactionCase):
         sol1.sequence = 2
         sol2.sequence = 3
         return so, visit, sol1, sol2
+
+    def _generate_so_with_one_visit_two_lines_and_descendants(self):
+        so = self._generate_sale_order()
+        visit = self._generate_visit(sale_order=so)
+        task_template = self._generate_task_template(structure=[2, 2, 2],
+                                                     names=['Parent', 'Child', 'Grandchild', 'Great-grandchild'])
+        product = self._generate_product(task_template=task_template)
+        sol1 = self._generate_sale_order_line(sale_order=so, product=product)
+        sol2 = self._generate_sale_order_line(sale_order=so, product=product)
+        visit.so_section_id.sequence = 1
+        sol1.sequence = 2
+        sol2.sequence = 3
+        return so, visit, sol1, sol2
diff --git a/bemade_fsm/tests/test_fsm_visit.py b/bemade_fsm/tests/test_fsm_visit.py
index 137410e..0121d9e 100644
--- a/bemade_fsm/tests/test_fsm_visit.py
+++ b/bemade_fsm/tests/test_fsm_visit.py
@@ -102,18 +102,19 @@ class FSMVisitTest(BemadeFSMBaseTest):
         self.assertEqual(len(so.order_line), 3)
 
     def test_marking_visit_task_done_completes_descendants(self):
-        so, visit, sol1, sol2 = self._generate_so_with_one_visit_two_lines()
+        so, visit, sol1, sol2 = self._generate_so_with_one_visit_two_lines_and_descendants()
         so.action_confirm()
-        parent, child1, child2 = visit.task_id, sol1.task_id, sol2.task_id
+        parent = visit.task_id
 
         parent.action_fsm_validate()
 
-        self.assertTrue(parent.is_closed)
-        self.assertTrue(child1.is_closed)
-        self.assertTrue(child2.is_closed)
-        self.assertEqual(sol1.qty_to_deliver, 0)
-        self.assertEqual(sol2.qty_to_deliver, 0)
-        self.assertTrue(visit.is_completed)
+        self._assert_is_done(parent)
+
+    def _assert_is_done(self, task):
+        """ Recursively assert all tasks in a hierarchy are complete """
+        self.assertTrue(task.is_closed)
+        for child in task.child_ids:
+            self._assert_is_done(child)
 
     def test_marking_visit_task_done_does_not_create_sale_order_line(self):
         so, visit, sol1, sol2 = self._generate_so_with_one_visit_two_lines()