diff -r 7356f71fb0a4 Lib/test/test_types.py
--- a/Lib/test/test_types.py	Fri May 29 09:06:05 2015 -0400
+++ b/Lib/test/test_types.py	Fri May 29 12:20:40 2015 -0400
@@ -1233,9 +1233,6 @@
         def gen():
             yield
 
-        self.assertFalse(isinstance(gen(), collections.abc.Coroutine))
-        self.assertFalse(isinstance(gen(), collections.abc.Awaitable))
-
         self.assertIs(types.coroutine(gen), gen)
 
         self.assertTrue(gen.__code__.co_flags & inspect.CO_ITERABLE_COROUTINE)
diff -r 7356f71fb0a4 Lib/types.py
--- a/Lib/types.py	Fri May 29 09:06:05 2015 -0400
+++ b/Lib/types.py	Fri May 29 12:20:40 2015 -0400
@@ -160,33 +160,21 @@
 
 import functools as _functools
 import collections.abc as _collections_abc
+import _types
 
 def coroutine(func):
     """Convert regular generator function to a coroutine."""
 
-    # We don't want to import 'dis' or 'inspect' just for
-    # these constants.
-    _CO_GENERATOR = 0x20
-    _CO_ITERABLE_COROUTINE = 0x100
-
     if not callable(func):
         raise TypeError('types.coroutine() expects a callable')
 
-    if (isinstance(func, FunctionType) and
-        isinstance(getattr(func, '__code__', None), CodeType) and
-        (func.__code__.co_flags & _CO_GENERATOR)):
-
-        # TODO: Implement this in C.
-        co = func.__code__
-        func.__code__ = CodeType(
-            co.co_argcount, co.co_kwonlyargcount, co.co_nlocals,
-            co.co_stacksize,
-            co.co_flags | _CO_ITERABLE_COROUTINE,
-            co.co_code,
-            co.co_consts, co.co_names, co.co_varnames, co.co_filename,
-            co.co_name, co.co_firstlineno, co.co_lnotab, co.co_freevars,
-            co.co_cellvars)
-        return func
+    if func.__class__ is FunctionType:
+        try:
+            _types._coroutine(func)
+        except TypeError:
+            pass
+        else:
+            return func
 
     @_functools.wraps(func)
     def wrapped(*args, **kwargs):
diff -r 7356f71fb0a4 Modules/Setup.dist
--- a/Modules/Setup.dist	Fri May 29 09:06:05 2015 -0400
+++ b/Modules/Setup.dist	Fri May 29 12:20:40 2015 -0400
@@ -119,6 +119,7 @@
 atexit atexitmodule.c      # Register functions to be run at interpreter-shutdown
 _stat _stat.c			# stat.h interface
 time timemodule.c	# -lm # time operations and variables
+_types _typesmodule.c    # Types module speedups
 
 # access to ISO C locale support
 _locale _localemodule.c  # -lintl
diff -r 7356f71fb0a4 Modules/_typesmodule.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Modules/_typesmodule.c	Fri May 29 12:20:40 2015 -0400
@@ -0,0 +1,59 @@
+/* Helpers for types module. */
+
+#include "Python.h"
+
+static PyObject *
+types_coroutine(PyObject *self, PyObject *func)
+{
+    PyCodeObject *func_code;
+
+    if (!PyFunction_Check(func)) {
+        PyErr_Format(PyExc_TypeError,
+                     "callable expected, got %.50s",
+                     Py_TYPE(func)->tp_name);
+        return NULL;
+    }
+
+    func_code = (PyCodeObject *)PyFunction_GET_CODE(func);
+
+    if (!(func_code->co_flags & CO_GENERATOR)) {
+        PyErr_SetString(PyExc_TypeError,
+                        "generator function expected");
+        return NULL;
+    }
+
+    func_code->co_flags |= CO_ITERABLE_COROUTINE;
+    Py_RETURN_NONE;
+}
+
+PyDoc_STRVAR(types_coroutine_doc,
+"_coroutine(func) -> None\n\
+\n\
+Applies CO_ITERABLE_COROUTINE to generator functions code object.\n\
+This is an internal helper for types.coroutine(), do not use this \n\
+function directly.\n");
+
+static PyMethodDef types_methods[] = {
+    {"_coroutine", types_coroutine, METH_O, types_coroutine_doc},
+    {NULL, NULL} /* sentinel */
+};
+
+PyDoc_STRVAR(module_doc, "Helpers for types module.\n");
+
+static struct PyModuleDef _typesmodule = {
+    PyModuleDef_HEAD_INIT,
+    "_types",
+    module_doc,
+    -1,
+    types_methods,
+    NULL,
+    NULL,
+    NULL,
+    NULL
+};
+
+PyMODINIT_FUNC
+PyInit__types(void)
+{
+    return PyModule_Create(&_typesmodule);
+}
diff -r 7356f71fb0a4 PC/config.c
--- a/PC/config.c	Fri May 29 09:06:05 2015 -0400
+++ b/PC/config.c	Fri May 29 12:20:40 2015 -0400
@@ -38,6 +38,7 @@
 extern PyObject* PyInit__collections(void);
 extern PyObject* PyInit__heapq(void);
 extern PyObject* PyInit__bisect(void);
+extern PyObject* PyInit__types(void);
 extern PyObject* PyInit__symtable(void);
 extern PyObject* PyInit_mmap(void);
 extern PyObject* PyInit__csv(void);
@@ -117,6 +118,7 @@
     {"itertools", PyInit_itertools},
     {"_collections", PyInit__collections},
     {"_symtable", PyInit__symtable},
+    {"_types", PyInit__types},
     {"mmap", PyInit_mmap},
     {"_csv", PyInit__csv},
     {"_sre", PyInit__sre},
diff -r 7356f71fb0a4 PCbuild/pythoncore.vcxproj
--- a/PCbuild/pythoncore.vcxproj	Fri May 29 09:06:05 2015 -0400
+++ b/PCbuild/pythoncore.vcxproj	Fri May 29 12:20:40 2015 -0400
@@ -227,6 +227,7 @@
     <ClCompile Include="..\Modules\_stat.c" />
     <ClCompile Include="..\Modules\_struct.c" />
     <ClCompile Include="..\Modules\_weakref.c" />
+    <ClCompile Include="..\Modules\_typesmodule.c" />
     <ClCompile Include="..\Modules\arraymodule.c" />
     <ClCompile Include="..\Modules\atexitmodule.c" />
     <ClCompile Include="..\Modules\audioop.c" />
@@ -415,4 +416,4 @@
   <Target Name="_WarnAboutToolset" BeforeTargets="PrepareForBuild" Condition="$(PlatformToolset) != 'v140'">
     <Warning Text="Toolset $(PlatformToolset) is not used for official builds. Your build may have errors or incompatibilities." />
   </Target>
-</Project>
\ No newline at end of file
+</Project>
diff -r 7356f71fb0a4 PCbuild/pythoncore.vcxproj.filters
--- a/PCbuild/pythoncore.vcxproj.filters	Fri May 29 09:06:05 2015 -0400
+++ b/PCbuild/pythoncore.vcxproj.filters	Fri May 29 12:20:40 2015 -0400
@@ -473,6 +473,9 @@
     <ClCompile Include="..\Modules\_randommodule.c">
       <Filter>Modules</Filter>
     </ClCompile>
+    <ClCompile Include="..\Modules\_typesmodule.c">
+      <Filter>Modules</Filter>
+    </ClCompile>
     <ClCompile Include="..\Modules\_sre.c">
       <Filter>Modules</Filter>
     </ClCompile>
@@ -974,4 +977,4 @@
       <Filter>Resource Files</Filter>
     </ResourceCompile>
   </ItemGroup>
-</Project>
\ No newline at end of file
+</Project>