diff --git a/monkey/tests/unit_tests/monkey_island/cc/repository/test_mongo_node_repository.py b/monkey/tests/unit_tests/monkey_island/cc/repository/test_mongo_node_repository.py
index b056cb575..9d1ee6279 100644
--- a/monkey/tests/unit_tests/monkey_island/cc/repository/test_mongo_node_repository.py
+++ b/monkey/tests/unit_tests/monkey_island/cc/repository/test_mongo_node_repository.py
@@ -158,7 +158,7 @@ def test_upsert_communication__find_one_fails(error_raising_node_repository):
 def test_upsert_communication__replace_one_fails(
     error_raising_mock_mongo_client, error_raising_node_repository
 ):
-    error_raising_mock_mongo_client.monkey_island.nodes.find_one = lambda _: None
+    error_raising_mock_mongo_client.monkey_island.nodes.find_one = MagicMock(return_value=None)
     with pytest.raises(StorageError):
         error_raising_node_repository.upsert_communication(1, 2, CommunicationType.SCANNED)
 
@@ -169,8 +169,10 @@ def test_upsert_communication__replace_one_matched_without_modify(
     mock_result = MagicMock()
     mock_result.matched_count = 1
     mock_result.modified_count = 0
-    error_raising_mock_mongo_client.monkey_island.nodes.find_one = lambda _: None
-    error_raising_mock_mongo_client.monkey_island.nodes.replace_one = lambda *_, **__: mock_result
+    error_raising_mock_mongo_client.monkey_island.nodes.find_one = MagicMock(return_value=None)
+    error_raising_mock_mongo_client.monkey_island.nodes.replace_one = MagicMock(
+        return_value=mock_result
+    )
 
     with pytest.raises(StorageError):
         error_raising_node_repository.upsert_communication(1, 2, CommunicationType.SCANNED)
@@ -182,8 +184,10 @@ def test_upsert_communication__replace_one_insert_fails(
     mock_result = MagicMock()
     mock_result.matched_count = 0
     mock_result.upserted_id = None
-    error_raising_mock_mongo_client.monkey_island.nodes.find_one = lambda _: None
-    error_raising_mock_mongo_client.monkey_island.nodes.replace_one = lambda *_, **__: mock_result
+    error_raising_mock_mongo_client.monkey_island.nodes.find_one = MagicMock(return_value=None)
+    error_raising_mock_mongo_client.monkey_island.nodes.replace_one = MagicMock(
+        return_value=mock_result
+    )
 
     with pytest.raises(StorageError):
         error_raising_node_repository.upsert_communication(1, 2, CommunicationType.SCANNED)