diff --git a/exercises/practice/collatz-conjecture/collatz_conjecture_test.py b/exercises/practice/collatz-conjecture/collatz_conjecture_test.py
index 306e3db7e7..2577df9f43 100644
--- a/exercises/practice/collatz-conjecture/collatz_conjecture_test.py
+++ b/exercises/practice/collatz-conjecture/collatz_conjecture_test.py
@@ -22,6 +22,9 @@ def test_even_and_odd_steps(self):
     def test_large_number_of_even_and_odd_steps(self):
         self.assertEqual(steps(1000000), 152)
 
+    def test_odd_number_start(self):
+        self.assertEqual(steps(25), 23)    
+
     def test_zero_is_an_error(self):
         with self.assertRaises(ValueError) as err:
             steps(0)