diff --git a/tests/unittests/test_handler/test_handler_write_files.py b/tests/unittests/test_handler/test_handler_write_files.py
index 41cc84f..88a4742 100644
--- a/tests/unittests/test_handler/test_handler_write_files.py
+++ b/tests/unittests/test_handler/test_handler_write_files.py
@@ -122,9 +122,7 @@ class TestDecodePerms(CiTestCase):
         """A string with invalid octal should warn and return default."""
         found = decode_perms("999", None, self.logger)
         self.assertIsNone(found)
-        self.assertEqual(
-            "WARNING: Undecodable permissions '999', returning default None\n",
-            self.logs.getvalue())
+        self.assertIn("WARNING: Undecodable", self.logs.getvalue())
 
 
 def _gzip_bytes(data):