diff --git a/robot/helper_plan_explain.py b/robot/helper_plan_explain.py
index 215940953..0a416f38a 100644
--- a/robot/helper_plan_explain.py
+++ b/robot/helper_plan_explain.py
@@ -49,7 +49,8 @@ def _test_explain_format() -> None:
     assert "decision_id" in data
     assert "context_snapshot" in data
     assert "rationale" in data
-    assert "alternatives_considered" in data
+    assert "alternatives" in data
+    assert isinstance(data["alternatives"], list)
     assert data["question"] == "What to build?"
     print("plan-explain-ok")