diff --git a/test/unit/app/tools/test_evaluation.py b/test/unit/app/tools/test_evaluation.py
index e571b5fd8898..72fe91c54b94 100644
--- a/test/unit/app/tools/test_evaluation.py
+++ b/test/unit/app/tools/test_evaluation.py
@@ -306,6 +306,7 @@ def __init__(self, app):
         self.options = Bunch(sanitize=False)
         self.check_values = True
         self.version_string_cmd = ""
+        self.credentials = []
 
     def test_thresh_param(self):
         elem = XML('<param name="thresh" type="integer" value="5" />')