diff --git a/CHANGES.txt b/CHANGES.txt
index 6dcd17e..d3c251a 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -6,7 +6,7 @@ Changelog
 
 - Add dependency on ``zdaemon`` (split off from ``ZODB``).
 
-- Claim support for Python 3.4 and 3.5.
+- Claim support for Python 3.4, 3.5 and PyPy.
 
 4.0.0a1 (2013-03-03)
 --------------------
diff --git a/setup.py b/setup.py
index 53681f1..6b26756 100644
--- a/setup.py
+++ b/setup.py
@@ -57,6 +57,9 @@ def read(*rnames):
         'Programming Language :: Python :: 3.3',
         'Programming Language :: Python :: 3.4',
         'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: Implementation',
+        'Programming Language :: Python :: Implementation :: CPython',
+        'Programming Language :: Python :: Implementation :: PyPy',
         'Natural Language :: English',
         'Operating System :: OS Independent',
         'Topic :: Internet :: WWW/HTTP',
diff --git a/src/zope/app/appsetup/testlayer.txt b/src/zope/app/appsetup/testlayer.txt
index c1b57b2..3bf6bff 100644
--- a/src/zope/app/appsetup/testlayer.txt
+++ b/src/zope/app/appsetup/testlayer.txt
@@ -79,8 +79,8 @@ We start with a derived layer, based on ZODBLayer that has some setup code:
   ...         transaction.commit()
 
   >>> layer = CustomZODBLayer(testpackage)
-  >>> layer
-  <CustomZODBLayer object at ...>
+  >>> layer.__class__
+  <class 'CustomZODBLayer'>
 
 Now, when running tests in this layer, each test sees the prepopulated
 database but is still isolated from other tests' changes:
diff --git a/tox.ini b/tox.ini
index c314fb9..20a9fd4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,5 +1,5 @@
 [tox]
-envlist = py26, py27, py33, py34, py35
+envlist = py26, py27, py33, py34, py35, pypy
 
 [testenv]
 commands =