diff --git a/exercises/concept/ellens-alien-game/classes_test.py b/exercises/concept/ellens-alien-game/classes_test.py
index 3d2b986be4..0d347734b0 100644
--- a/exercises/concept/ellens-alien-game/classes_test.py
+++ b/exercises/concept/ellens-alien-game/classes_test.py
@@ -199,6 +199,9 @@ def test_new_aliens_collection(self):
         test_data = [(-2, 6), (1, 5), (-4, -3)]
         actual_result = new_aliens_collection(test_data)
 
+        length_error_message = f"Expected {len(test_data)} Aliens, got {len(actual_result)}"
+        self.assertEqual(len(actual_result), len(test_data), msg=length_error_message)
+
         error_message = "new_aliens_collection() must return a list of Alien objects."
 
         for obj in actual_result: