diff --git a/tests/functional/testplan/testing/multitest/test_multitest_parts.py b/tests/functional/testplan/testing/multitest/test_multitest_parts.py
index e13e7c24c..933c07237 100644
--- a/tests/functional/testplan/testing/multitest/test_multitest_parts.py
+++ b/tests/functional/testplan/testing/multitest/test_multitest_parts.py
@@ -1,3 +1,4 @@
+import re
 from itertools import chain, cycle, repeat
 from operator import eq
 
@@ -159,7 +160,7 @@ def test_multi_parts_incorrect_schedule():
     )
 
 
-def test_multi_parts_duplicate_part():
+def test_multi_parts_duplicate_part(mocker):
     """
     Execute MultiTest parts with a part of MultiTest has been
     scheduled twice and automatically be filtered out.
@@ -167,6 +168,7 @@ def test_multi_parts_duplicate_part():
     since multi_part_uid has no functional effect now, original test is invalid
     preserved for simple backward compatibility test, i.e. no exception raised
     """
+    mock_warn = mocker.patch("warnings.warn")
     plan = TestplanMock(name="plan", merge_scheduled_parts=True)
     pool = ThreadPool(name="MyThreadPool", size=2)
     plan.add_resource(pool)
@@ -179,6 +181,8 @@ def test_multi_parts_duplicate_part():
         task = Task(target=get_mtest_with_custom_uid(part_tuple=(1, 3)))
         plan.schedule(task, resource="MyThreadPool")
 
+    assert mock_warn.call_count == 4
+    assert re.search(r"remove.*multi_part_uid", mock_warn.call_args[0][0])
     assert len(plan._tests) == 3
     assert plan.run().run is True