diff --git a/CHANGELOG b/CHANGELOG
index e20f30dd3..207aa899e 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,6 +1,7 @@
 Changes between 2.0.3 and 2.1.0.DEV
 ----------------------------------------------
 
+- fix issue58 and issue59: new assertion code fixes
 - merge Benjamin's assertionrewrite branch: now assertions
   for test modules on python 2.6 and above are done by rewriting
   the AST and saving the pyc file before the test module is imported.
diff --git a/_pytest/__init__.py b/_pytest/__init__.py
index 596e2bcdf..7f1034c8e 100644
--- a/_pytest/__init__.py
+++ b/_pytest/__init__.py
@@ -1,2 +1,2 @@
 #
-__version__ = '2.1.0.dev4'
+__version__ = '2.1.0.dev5'
diff --git a/_pytest/assertion/__init__.py b/_pytest/assertion/__init__.py
index 33823b877..fec80a1bd 100644
--- a/_pytest/assertion/__init__.py
+++ b/_pytest/assertion/__init__.py
@@ -7,8 +7,6 @@ import pytest
 from _pytest.monkeypatch import monkeypatch
 from _pytest.assertion import util
 
-REWRITING_AVAILABLE = "_ast" in sys.builtin_module_names
-
 def pytest_addoption(parser):
     group = parser.getgroup("debugconfig")
     group.addoption('--assertmode', action="store", dest="assertmode",
@@ -40,8 +38,11 @@ def pytest_configure(config):
         mode = "off"
     elif mode == "default":
         mode = "rewrite"
-    if mode == "on" and not REWRITING_AVAILABLE:
-        mode = "reinterp"
+    if mode == "rewrite":
+        try:
+            import ast
+        except ImportError:
+            mode = "reinterp"
     if mode != "off":
         _load_modules(mode)
         def callbinrepr(op, left, right):
diff --git a/setup.py b/setup.py
index c93e2d922..084bb498f 100644
--- a/setup.py
+++ b/setup.py
@@ -22,7 +22,7 @@ def main():
         name='pytest',
         description='py.test: simple powerful testing with Python',
         long_description = long_description,
-        version='2.1.0.dev4',
+        version='2.1.0.dev5',
         url='http://pytest.org',
         license='MIT license',
         platforms=['unix', 'linux', 'osx', 'cygwin', 'win32'],
diff --git a/testing/test_assertion.py b/testing/test_assertion.py
index 0a727ce62..a00b430fd 100644
--- a/testing/test_assertion.py
+++ b/testing/test_assertion.py
@@ -120,6 +120,7 @@ class TestAssert_reprcompare:
         expl = ' '.join(callequal('foo', 'bar'))
         assert 'raised in repr()' not in expl
 
+@needsnewassert
 def test_rewritten(testdir):
     testdir.makepyfile("""
         def test_rewritten():