diff --git a/isso/compat.py b/isso/compat.py
index e38ecc5..8e5cb10 100644
--- a/isso/compat.py
+++ b/isso/compat.py
@@ -10,7 +10,7 @@ except NameError:        # Python 3
     string_types = (str, )
 
 if not PY2K:
-    buffer = memoryview
+    buffer = memoryview  # noqa: F821 undefined name 'memoryview' in Python 2.6
     filter, map, zip = filter, map, zip
     iteritems = lambda dikt: iter(dikt.items())  # noqa: E731
     from functools import reduce