diff --git a/jedi/evaluate/compiled/access.py b/jedi/evaluate/compiled/access.py
index 9fb3b076..daf3c513 100644
--- a/jedi/evaluate/compiled/access.py
+++ b/jedi/evaluate/compiled/access.py
@@ -447,14 +447,31 @@ def _is_class_instance(obj):
         return cls != type and not issubclass(cls, NOT_CLASS_TYPES)
 
 
+if py_version >= 35:
+    async def _coroutine(): pass
+    _coroutine = _coroutine()
+    CoroutineType = type(_coroutine)
+    _coroutine.close()  # Prevent ResourceWarning
+else:
+    _coroutine = None
+
+if py_version >= 36:
+    async def _async_generator():
+        yield
+    _async_generator = _async_generator()
+    AsyncGeneratorType = type(_async_generator)
+else:
+    _async_generator = None
+
+
 class _SPECIAL_OBJECTS(object):
     FUNCTION_CLASS = types.FunctionType
     METHOD_CLASS = type(DirectObjectAccess.py__bool__)
     MODULE_CLASS = types.ModuleType
     GENERATOR_OBJECT = _a_generator(1.0)
     BUILTINS = builtins
-    COROUTINE_TYPE = getattr(types, 'CoroutineType', None)
-    ASYNC_GENERATOR_TYPE = getattr(types, 'AsyncGeneratorType', None)
+    COROUTINE = _coroutine
+    ASYNC_GENERATOR = _async_generator
 
 
 def get_special_object(evaluator, identifier):
diff --git a/jedi/evaluate/context/asynchronous.py b/jedi/evaluate/context/asynchronous.py
index 1061ebbf..8b82dc35 100644
--- a/jedi/evaluate/context/asynchronous.py
+++ b/jedi/evaluate/context/asynchronous.py
@@ -1,5 +1,4 @@
 from jedi.evaluate.filters import publish_method, BuiltinOverwrite
-from jedi.evaluate.base_context import ContextSet
 
 
 class AsyncBase(BuiltinOverwrite):
@@ -16,7 +15,7 @@ class AsyncBase(BuiltinOverwrite):
 
 
 class Coroutine(AsyncBase):
-    special_object_identifier = u'COROUTINE_TYPE'
+    special_object_identifier = u'COROUTINE'
 
     @publish_method('__await__')
     def _await(self):
@@ -25,11 +24,7 @@ class Coroutine(AsyncBase):
 
 class AsyncGenerator(AsyncBase):
     """Handling of `yield` functions."""
-    special_object_identifier = u'ASYNC_GENERATOR_TYPE'
-
-    @publish_method('__anext__')
-    def py__anext__(self):
-        return ContextSet.from_sets(lazy_context.infer() for lazy_context in self.py__aiter__())
+    special_object_identifier = u'ASYNC_GENERATOR'
 
     def py__aiter__(self):
         return self._func_execution_context.get_yield_lazy_contexts(is_async=True)
diff --git a/jedi/evaluate/context/iterable.py b/jedi/evaluate/context/iterable.py
index baffedfc..d656e0b4 100644
--- a/jedi/evaluate/context/iterable.py
+++ b/jedi/evaluate/context/iterable.py
@@ -106,7 +106,7 @@ def comprehension_from_atom(evaluator, context, atom):
 
 
 class ComprehensionMixin(object):
-    def __init__(self, evaluator, defining_context, atom, is_async=False):
+    def __init__(self, evaluator, defining_context, atom):
         super(ComprehensionMixin, self).__init__(evaluator)
         self._defining_context = defining_context
         self._atom = atom
diff --git a/test/completion/async_.py b/test/completion/async_.py
index 95a98853..41d34140 100644
--- a/test/completion/async_.py
+++ b/test/completion/async_.py
@@ -41,6 +41,8 @@ async def wrapper():
 
 #? ['__anext__']
 asgen().__ane
+#? []
+asgen().mro
 
 
 async def x2():