diff --git a/CHANGELOG b/CHANGELOG
index a8aea020b..354553594 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -39,6 +39,8 @@ Unreleased
   arg is an lambda and thus the example will work.  Thanks Alex Gaynor
   for bringing it up.
 
+- xfail a test on pypy that checks wrong encoding/ascii (pypy does
+  not error out). fixes issue385.
 
 Changes between 2.4.1 and 2.4.2
 -----------------------------------
diff --git a/testing/test_assertrewrite.py b/testing/test_assertrewrite.py
index 5bc7a9b51..556249617 100644
--- a/testing/test_assertrewrite.py
+++ b/testing/test_assertrewrite.py
@@ -441,8 +441,9 @@ class TestAssertionRewriteHookDetails(object):
         ])
 
     @pytest.mark.skipif("sys.version_info[0] >= 3")
+    @pytest.mark.xfail("hasattr(sys, 'pypy_translation_info')")
     def test_assume_ascii(self, testdir):
-        content = "u'\xe2\x99\xa5'"
+        content = "u'\xe2\x99\xa5\x01\xfe'"
         testdir.tmpdir.join("test_encoding.py").write(content, "wb")
         res = testdir.runpytest()
         assert res.ret != 0
diff --git a/tox.ini b/tox.ini
index ae14220fc..2719a9b70 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,6 +1,6 @@
 [tox]
 distshare={homedir}/.tox/distshare
-envlist=flakes,py25,py26,py27,py27-nobyte,py32,py33,py27-xdist,trial
+envlist=flakes,py25,py26,py27,pypy,py27-nobyte,py32,py33,py27-xdist,trial
 
 [testenv]
 changedir=testing