diff --git a/tests/unit_tests/weightwindows/test.py b/tests/unit_tests/weightwindows/test.py
index aaa0bb523c..4f986e064c 100644
--- a/tests/unit_tests/weightwindows/test.py
+++ b/tests/unit_tests/weightwindows/test.py
@@ -126,6 +126,7 @@ def test_weightwindows(model):
 
         model.settings.weight_windows = [ww_n, ww_p]
 
+        _ = [str(ww) for ww in model.settings.weight_windows]
 
         # run again with variance reduction on
         model.settings.weight_windows_on = True