diff --git a/py/_builtin.py b/py/_builtin.py
index 52ee9d79..ddc89fc7 100644
--- a/py/_builtin.py
+++ b/py/_builtin.py
@@ -1,120 +1,21 @@
 import sys
 
-try:
-    reversed = reversed
-except NameError:
-    def reversed(sequence):
-        """reversed(sequence) -> reverse iterator over values of the sequence
-
-        Return a reverse iterator
-        """
-        if hasattr(sequence, '__reversed__'):
-            return sequence.__reversed__()
-        if not hasattr(sequence, '__getitem__'):
-            raise TypeError("argument to reversed() must be a sequence")
-        return reversed_iterator(sequence)
-
-    class reversed_iterator(object):
-
-        def __init__(self, seq):
-            self.seq = seq
-            self.remaining = len(seq)
-
-        def __iter__(self):
-            return self
-
-        def next(self):
-            i = self.remaining
-            if i > 0:
-                i -= 1
-                item = self.seq[i]
-                self.remaining = i
-                return item
-            raise StopIteration
-
-        def __length_hint__(self):
-            return self.remaining
-
-try:
-    any = any
-except NameError:
-    def any(iterable):
-        for x in iterable:
-            if x:
-                return True
-        return False
-
-try:
-    all = all
-except NameError:
-    def all(iterable):
-        for x in iterable:
-            if not x:
-                return False
-        return True
-
-try:
-    sorted = sorted
-except NameError:
-    builtin_cmp = cmp # need to use cmp as keyword arg
-
-    def sorted(iterable, cmp=None, key=None, reverse=0):
-        use_cmp = None
-        if key is not None:
-            if cmp is None:
-                def use_cmp(x, y):
-                    return builtin_cmp(x[0], y[0])
-            else:
-                def use_cmp(x, y):
-                    return cmp(x[0], y[0])
-            l = [(key(element), element) for element in iterable]
-        else:
-            if cmp is not None:
-                use_cmp = cmp
-            l = list(iterable)
-        if use_cmp is not None:
-            l.sort(use_cmp)
-        else:
-            l.sort()
-        if reverse:
-            l.reverse()
-        if key is not None:
-            return [element for (_, element) in l]
-        return l
-
-try:
-    set, frozenset = set, frozenset
-except NameError:
-    from sets import set, frozenset
-
-# pass through
-enumerate = enumerate
-
-try:
-    BaseException = BaseException
-except NameError:
-    BaseException = Exception
-
-try:
-    GeneratorExit = GeneratorExit
-except NameError:
-    class GeneratorExit(Exception):
-        """ This exception is never raised, it is there to make it possible to
-        write code compatible with CPython 2.5 even in lower CPython
-        versions."""
-        pass
-    GeneratorExit.__module__ = 'exceptions'
 
+# Passthrough for builtins supported with py27.
+BaseException = BaseException
+GeneratorExit = GeneratorExit
 _sysex = (KeyboardInterrupt, SystemExit, MemoryError, GeneratorExit)
+all = all
+any = any
+callable = callable
+enumerate = enumerate
+reversed = reversed
+set, frozenset = set, frozenset
+sorted = sorted
 
-try:
-    callable = callable
-except NameError:
-    def callable(obj):
-        return hasattr(obj, "__call__")
 
 if sys.version_info >= (3, 0):
-    exec ("print_ = print ; exec_=exec")
+    exec("print_ = print ; exec_=exec")
     import builtins
 
     # some backward compatibility helpers
@@ -131,13 +32,13 @@ def _totext(obj, encoding=None, errors=None):
 
     def _isbytes(x):
         return isinstance(x, bytes)
+
     def _istext(x):
         return isinstance(x, str)
 
     text = str
     bytes = bytes
 
-
     def _getimself(function):
         return getattr(function, '__self__', None)
 
diff --git a/testing/root/test_builtin.py b/testing/root/test_builtin.py
index a6f1a3c7..287c60d5 100644
--- a/testing/root/test_builtin.py
+++ b/testing/root/test_builtin.py
@@ -1,7 +1,7 @@
 import sys
 import types
 import py
-from py.builtin import set, frozenset, reversed, sorted
+from py.builtin import set, frozenset
 
 def test_enumerate():
     l = [0,1,2]
@@ -53,29 +53,6 @@ def test_frozenset():
     s = set([frozenset([0, 1]), frozenset([1, 0])])
     assert len(s) == 1
 
-def test_sorted():
-    if sorted == py.builtin.sorted:
-        return # don't test a real builtin
-    for s in [py.builtin.sorted]:
-        def test():
-            assert s([3, 2, 1]) == [1, 2, 3]
-            assert s([1, 2, 3], reverse=True) == [3, 2, 1]
-            l = s([1, 2, 3, 4, 5, 6], key=lambda x: x % 2)
-            assert l == [2, 4, 6, 1, 3, 5]
-            l = s([1, 2, 3, 4], cmp=lambda x, y: -cmp(x, y))
-            assert l == [4, 3, 2, 1]
-            l = s([1, 2, 3, 4], cmp=lambda x, y: -cmp(x, y),
-                        key=lambda x: x % 2)
-            assert l == [1, 3, 2, 4]
-
-            def compare(x, y):
-                assert type(x) == str
-                assert type(y) == str
-                return cmp(x, y)
-            data = 'The quick Brown fox Jumped over The lazy Dog'.split()
-            s(data, cmp=compare, key=str.lower)
-        yield test
-
 
 def test_print_simple():
     from py.builtin import print_
@@ -116,7 +93,7 @@ class A:
 
 def test_getfuncdict():
     def f():
-        pass
+        raise NotImplementedError
     f.x = 4
     assert py.builtin._getfuncdict(f)["x"] == 4
     assert py.builtin._getfuncdict(2) is None
diff --git a/tox.ini b/tox.ini
index 45f22524..dd8828b2 100644
--- a/tox.ini
+++ b/tox.ini
@@ -39,3 +39,6 @@ source = .
 parallel = 1
 [coverage:report]
 include = py/*,testing/*
+exclude_lines =
+    #\s*(pragma|PRAGMA)[:\s]?\s*(no|NO)\s*(cover|COVER)
+    ^\s*raise NotImplementedError\b