diff --git a/tests/test_tree_sequences_with_neutral_mutations.py b/tests/test_tree_sequences_with_neutral_mutations.py
index 2993a1659..2f1b5f130 100644
--- a/tests/test_tree_sequences_with_neutral_mutations.py
+++ b/tests/test_tree_sequences_with_neutral_mutations.py
@@ -183,5 +183,9 @@ def test_trigger_final_simplification_with_fixations_to_remove():
     )
 
 
+def test_track_mutation_counts():
+    raise NotImplementedError("let's get at issue #1341!")
+
+
 if __name__ == "__main__":
     unittest.main()