diff --git a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_plan.py b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_plan.py
index 7754446882..75ab9944be 100644
--- a/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_plan.py
+++ b/src/ifcopenshell-python/ifcopenshell/api/sequence/add_work_plan.py
@@ -71,10 +71,11 @@ def add_work_plan(
         work_plan.Creators = [user.ThePerson]
     work_plan.StartTime = ifcopenshell.api.sequence.add_date_time(file, datetime.now())
 
-    context = file.by_type("IfcContext")[0]
-    ifcopenshell.api.project.assign_declaration(
-        file,
-        definitions=[work_plan],
-        relating_context=context,
-    )
+    if file.schema != "IFC2X3":
+        context = file.by_type("IfcContext")[0]
+        ifcopenshell.api.project.assign_declaration(
+            file,
+            definitions=[work_plan],
+            relating_context=context,
+        )
     return work_plan
diff --git a/src/ifcopenshell-python/ifcopenshell/util/sequence.py b/src/ifcopenshell-python/ifcopenshell/util/sequence.py
index babcfd6fbc..930184ecdb 100644
--- a/src/ifcopenshell-python/ifcopenshell/util/sequence.py
+++ b/src/ifcopenshell-python/ifcopenshell/util/sequence.py
@@ -18,6 +18,7 @@
 
 import datetime
 import ifcopenshell.util.date
+import ifcopenshell.util.element
 from math import floor
 from functools import cache
 from typing import Union, Literal, Optional
@@ -280,7 +281,7 @@ def get_task_work_schedule(task: ifcopenshell.entity_instance) -> Union[ifcopens
 
 
 def get_nested_tasks(task: ifcopenshell.entity_instance) -> list[ifcopenshell.entity_instance]:
-    return [object for rel in task.IsNestedBy or [] for object in rel.RelatedObjects if object.is_a("IfcTask")]
+    return [obj for obj in ifcopenshell.util.element.get_components(task) if obj.is_a("IfcTask")]
 
 
 def get_parent_task(task: ifcopenshell.entity_instance) -> Union[ifcopenshell.entity_instance, None]:
diff --git a/src/ifcopenshell-python/test/api/sequence/test_copy_work_schedule.py b/src/ifcopenshell-python/test/api/sequence/test_copy_work_schedule.py
index 7bb686ceb6..368738eeaf 100644
--- a/src/ifcopenshell-python/test/api/sequence/test_copy_work_schedule.py
+++ b/src/ifcopenshell-python/test/api/sequence/test_copy_work_schedule.py
@@ -43,5 +43,9 @@ class TestCopyWorkSchedule(test.bootstrap.IFC4):
         assert len(new_tasks.intersection(old_cost_items)) == 0
 
 
+class TestCopyWorkScheduleIFC2X3(test.bootstrap.IFC2X3, TestCopyWorkSchedule):
+    pass
+
+
 class TestCopyWorkScheduleIFC4X3(test.bootstrap.IFC4X3, TestCopyWorkSchedule):
     pass