With the release of BTrees 4.2.0 we can also claim to support Python 3.5, so test this.

.travis.yml

@@ -8,6 +8,7 @@ python:
     - 3.2
     - 3.3
     - 3.4
+    - 3.5
 install:
     # First install a newer pip so that it can use the wheel cache
     # (only needed until travis upgrades pip to 7.x; note that the 3.5

CHANGES.rst

@@ -2,7 +2,7 @@
  Change History
 ================
 
-4.2.1 (unreleased)
+4.3.0 (unreleased)
 ==================
 
 - Make the ``zodbpickle`` dependency required and not conditional.
@@ -11,6 +11,8 @@
   only impacts users of that version.  See
   https://github.com/zopefoundation/ZODB/pull/42.
 
+- Add support for Python 3.5.
+
 4.2.0 (2015-06-02)
 ==================
 

setup.py

@@ -20,7 +20,7 @@ to application logic.  ZODB includes features such as a plugable storage
 interface, rich transaction support, and undo.
 """
 
-version = "4.2.1.dev0"
+version = "4.3.0.dev0"
 
 import os
 import sys
@@ -52,6 +52,7 @@ Programming Language :: Python :: 3
 Programming Language :: Python :: 3.2
 Programming Language :: Python :: 3.3
 Programming Language :: Python :: 3.4
+Programming Language :: Python :: 3.5
 Programming Language :: Python :: Implementation :: CPython
 Programming Language :: Python :: Implementation :: PyPy
 Topic :: Database
@@ -156,7 +157,7 @@ setup(name="ZODB",
       },
       install_requires = [
         'persistent >= 4.1.0',
-        'BTrees >= 4.1.3',
+        'BTrees >= 4.2.0',
         'ZConfig',
         'transaction >= 1.4.4',
         'six',

tox.ini

@@ -2,7 +2,7 @@
 # Jython 2.7rc2 does work, but unfortunately has an issue running
 # with Tox 1.9.2 (http://bugs.jython.org/issue2325)
 #envlist = py26,py27,py32,py33,py34,pypy,simple,jython,pypy3
-envlist = py26,py27,py32,py33,py34,pypy,simple,pypy3
+envlist = py26,py27,py32,py33,py34,py35,pypy,simple,pypy3
 
 [testenv]
 commands =