diff --git a/src/test/py/test_logical_operations.py b/src/test/py/test_logical_operations.py
index 968a39d..c64d566 100644
--- a/src/test/py/test_logical_operations.py
+++ b/src/test/py/test_logical_operations.py
@@ -42,6 +42,9 @@ class calculationsWithRoots(unittest.TestCase):
     def test_one_zero_1_or_0_equals_1(self):
         self.assertEqual(one_zero(1, 0), 1)
 
+    def test_one_zero_1_or_0_equals_11(self):
+        self.assertEqual(one_zero(0, 0), None)
+
 
 if __name__ == "__main__":
     unittest.main()