diff --git a/tests/test_direct_api.py b/tests/test_direct_api.py
index 373d3415..e34c065a 100644
--- a/tests/test_direct_api.py
+++ b/tests/test_direct_api.py
@@ -2993,7 +2993,7 @@ def test_group_by_str_repr(self):
             "  <build123d.topology.Edge at 0x1277fec6d90>]]",
         ]
 
-        self.assertDunderStrEqual(nonagon.edges().group_by(Axis.X), expected)
+        self.assertDunderStrEqual(str(nonagon.edges().group_by(Axis.X)), expected)
 
         expected_repr = (
             "[[<build123d.topology.Edge object at 0x000001277FEC6D90>],"