diff --git a/tests/test_measure.py b/tests/test_measure.py
index fa8b528..79bb0fb 100644
--- a/tests/test_measure.py
+++ b/tests/test_measure.py
@@ -36,9 +36,15 @@ def test_len_slice(self):
         with self.assertRaises(measure.UnknownSliceLengthException):
             measure.len_slice(slice(None))
 
+        with self.assertRaises(measure.UnknownSliceLengthException):
+            measure.len_slice(slice(0, -1, 1))
+
         with self.assertRaises(measure.UnknownSliceLengthException):
             measure.len_slice(slice(None, None, -1))
 
+        with self.assertRaises(measure.UnknownSliceLengthException):
+            measure.len_slice(slice(-1, 1, -1))
+
         for size in [10, 11, 12]:
             excess = size + 3
             each_range = range(size)