diff --git a/src/allmydata/uri.py b/src/allmydata/uri.py
index bad0dd9df..2c367cafe 100644
--- a/src/allmydata/uri.py
+++ b/src/allmydata/uri.py
@@ -13,7 +13,8 @@ from __future__ import unicode_literals
 
 from future.utils import PY2
 if PY2:
-    # Don't import bytes or str, to prevent leaks.
+    # Don't import bytes or str, to prevent future's newbytes leaking and
+    # breaking code that only expects normal bytes.
     from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, dict, list, object, range, max, min  # noqa: F401
     str = unicode