diff --git a/test/test_serialize_export_import.py b/test/test_serialize_export_import.py
index 9ea2f998bde6d5d1833a0f8b5d5542d076843ad8..eec9f433bb50901672a06e93f5e93fa677e3742f 100644
--- a/test/test_serialize_export_import.py
+++ b/test/test_serialize_export_import.py
@@ -102,7 +102,7 @@ class SerializeTest(unittest.TestCase):
             "invalid_key": "All keys do not exist",
         }
         file = open(invalid_soi_file_path, "w")
-        file.write(str(invalid_serialization))
+        file.write(json.dumps(invalid_serialization))
         file.close()
         # Assert invalid serialization throws error on import
         with self.assertRaises(ValueError) as error: