diff --git a/flake8/tests/test_mccabe.py b/flake8/tests/test_mccabe.py
index 887599f..1814699 100644
--- a/flake8/tests/test_mccabe.py
+++ b/flake8/tests/test_mccabe.py
@@ -36,6 +36,6 @@ class McCabeTest(unittest.TestCase):
         self.assertEqual(get_code_complexity(_GLOBAL, 1), 2)
         self.out.seek(0)
         res = self.out.read().strip().split('\n')
-        wanted = ["stdin:5:1: W901 'a' is too complex (4)",
-                  "stdin:2:1: W901 'Loop 2' is too complex (2)"]
+        wanted = ["stdin:5:1: C901 'a' is too complex (4)",
+                  "stdin:2:1: C901 'Loop 2' is too complex (2)"]
         self.assertEqual(res, wanted)