diff --git a/tests/laborious/activities/test_api.py b/tests/laborious/activities/test_api.py
index 8099488..525dbec 100644
--- a/tests/laborious/activities/test_api.py
+++ b/tests/laborious/activities/test_api.py
@@ -386,7 +386,8 @@ def test_close(mock_shutdown, api):
     api.close()
 
     api.pi_web_api_client.close.assert_called_once()
-    mock_shutdown.assert_called_once_with(api)
+    # Other instances collected by GC during the test also hit the patched shutdown.
+    assert mock_shutdown.call_args_list.count(call(api)) == 1
 
 
 def test_process_pi_web_api_response_success(api):
diff --git a/tests/laborious/activities/test_gates.py b/tests/laborious/activities/test_gates.py
index 9a4cd3e..5f28509 100644
--- a/tests/laborious/activities/test_gates.py
+++ b/tests/laborious/activities/test_gates.py
@@ -991,7 +991,8 @@ def test_close_disposes_minio_repository(mock_shutdown):
     gates.close()
     minio.close.assert_called_once()
     assert gates.minio_repository is None
-    mock_shutdown.assert_called_once_with(gates)
+    # Other instances collected by GC during the test also hit the patched shutdown.
+    assert mock_shutdown.call_args_list.count(call(gates)) == 1
 
 
 @patch.object(SientiaMonitoring, 'shutdown')
@@ -1004,4 +1005,5 @@ def test_close_without_minio_repository(mock_shutdown):
         metrics_controller=MagicMock(spec=MetricsController),
     )
     gates.close()
-    mock_shutdown.assert_called_once_with(gates)
+    # Other instances collected by GC during the test also hit the patched shutdown.
+    assert mock_shutdown.call_args_list.count(call(gates)) == 1
diff --git a/tests/laborious/activities/test_storage.py b/tests/laborious/activities/test_storage.py
index 616ee4a..6285b12 100644
--- a/tests/laborious/activities/test_storage.py
+++ b/tests/laborious/activities/test_storage.py
@@ -1,6 +1,6 @@
 import datetime
 import os
-from unittest.mock import ANY, MagicMock, patch
+from unittest.mock import ANY, MagicMock, call, patch
 
 from pytest import fixture, raises
 from sientia_do.notifications.models import NotificationLevel
@@ -134,7 +134,8 @@ def test_close(storage, _patch_monitoring_shutdown):
     storage.close()
 
     assert storage.minio_repository is None
-    _patch_monitoring_shutdown.assert_called_once_with(storage)
+    # Other instances collected by GC during the test also hit the patched shutdown.
+    assert _patch_monitoring_shutdown.call_args_list.count(call(storage)) == 1
 
 
 def test_close_when_minio_repository_already_none(storage, _patch_monitoring_shutdown):
@@ -144,7 +145,8 @@ def test_close_when_minio_repository_already_none(storage, _patch_monitoring_shu
     storage.close()
 
     assert storage.minio_repository is None
-    _patch_monitoring_shutdown.assert_called_once_with(storage)
+    # Other instances collected by GC during the test also hit the patched shutdown.
+    assert _patch_monitoring_shutdown.call_args_list.count(call(storage)) == 1
 
 
 def test_load_query_with_minio_offload_no_rows(storage):