diff --git a/tests/sources/test_transformer.py b/tests/sources/test_transformer.py
index 918dd49..33ecb84 100644
--- a/tests/sources/test_transformer.py
+++ b/tests/sources/test_transformer.py
@@ -1,3 +1,4 @@
+from pathlib import Path
 from unittest.mock import patch
 
 import pytest
@@ -62,11 +63,11 @@ def test_xmltransformer_transform_and_write_output_files_writes_output_files(
 ):
     output_file = str(tmp_path / "output_file.json")
     transformer = XmlTransformer("cool-repo", oai_pmh_records)
+    assert not Path(tmp_path / "output_file.json").exists()
+    assert not Path(tmp_path / "output_file.txt").exists()
     transformer.transform_and_write_output_files(output_file)
-    output_files = list(tmp_path.iterdir())
-    assert len(output_files) == 2
-    assert output_files[0].name == "output_file.json"
-    assert output_files[1].name == "output_file.txt"
+    assert Path(tmp_path / "output_file.json").exists()
+    assert Path(tmp_path / "output_file.txt").exists()
 
 
 def test_xmltransformer_transform_and_write_output_files_no_txt_file_if_not_needed(