diff --git a/Lib/pickle.py b/Lib/pickle.py
index 1f551d67b07..2805dfb7d71 100644
--- a/Lib/pickle.py
+++ b/Lib/pickle.py
@@ -255,6 +255,7 @@ def save(self, object):
 
         t = type(object)
 
+        # XXX Why are tuples a special case here?
         if (t is TupleType) and (len(object) == 0):
             if self.bin:
                 self.save_empty_tuple(object)