diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 2dd5f18dc4..b10ca1c91f 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -1445,6 +1445,8 @@ def test_many_lines():
             (None, 9, 0),
             (None, 0, 0),
             (0, 0, 0),
+            (0, 1000, 0),
+            (1000, 0, 0),
         ),
     )
     def test_truncation_with_ini(