diff --git a/CI_REQUIREMENTS.txt b/CI_REQUIREMENTS.txt
index 5d1ee86..ec7b2d2 100644
--- a/CI_REQUIREMENTS.txt
+++ b/CI_REQUIREMENTS.txt
@@ -1,5 +1,6 @@
 typing >= 3.6 ; python_version < "3.8"
 mock; python_version == "2.7"
 futures>=3.1; python_version == "2.7"
+greenlet <= 0.4.13
 gevent >= 1.2, <1.3.0 ; platform_python_implementation == "PyPy"
 gevent >= 1.2 ; platform_python_implementation != "PyPy"
diff --git a/threaded/__init__.py b/threaded/__init__.py
index 141030d..f0b77da 100644
--- a/threaded/__init__.py
+++ b/threaded/__init__.py
@@ -46,7 +46,7 @@
     try:  # pragma: no cover
         from ._gthreadpooled2 import GThreadPooled, gthreadpooled
     except ImportError:  # pragma: no cover
-        GThreadPooled = gthreadpooled = None  # type: ignore
+        GThreadPooled = gthreadpooled = None
 # pylint: enable=no-name-in-module
 
 
diff --git a/threaded/_base_gthreadpooled.py b/threaded/_base_gthreadpooled.py
index c05ed4b..52ad620 100644
--- a/threaded/_base_gthreadpooled.py
+++ b/threaded/_base_gthreadpooled.py
@@ -39,7 +39,7 @@ class BaseGThreadPooled(_base_threaded.APIPooled):
     # pylint: disable=arguments-differ
     @classmethod
     def configure(
-        cls,
+        cls,  # type: typing.Type[BaseGThreadPooled]
         max_workers=None,  # type: typing.Optional[int]
         hub=None  # type: typing.Optional[gevent.hub.Hub]
     ):  # type: (...) -> None
diff --git a/threaded/_base_gthreadpooled.pyi b/threaded/_base_gthreadpooled.pyi
index b61fb09..c648e0b 100644
--- a/threaded/_base_gthreadpooled.pyi
+++ b/threaded/_base_gthreadpooled.pyi
@@ -6,7 +6,7 @@ from . import _base_threaded
 class BaseGThreadPooled(_base_threaded.APIPooled):
     @classmethod
     def configure(
-        cls,
+        cls: typing.Type[BaseGThreadPooled],
         max_workers: typing.Optional[int]=...,
         hub: typing.Optional[gevent.hub.Hub]=...
     ) -> None: ...
diff --git a/threaded/_base_threaded.py b/threaded/_base_threaded.py
index 5943695..d486676 100644
--- a/threaded/_base_threaded.py
+++ b/threaded/_base_threaded.py
@@ -16,6 +16,7 @@
 
 from __future__ import absolute_import
 
+import abc
 # noinspection PyCompatibility
 import concurrent.futures
 import threading
@@ -43,7 +44,7 @@ def cpu_count():  # type: () -> int
 )
 
 
-class APIPooled(_class_decorator.BaseDecorator):
+class APIPooled(six.with_metaclass(abc.ABCMeta, _class_decorator.BaseDecorator)):
     """API description for pooled."""
 
     __slots__ = ()
@@ -52,7 +53,7 @@ class APIPooled(_class_decorator.BaseDecorator):
 
     @classmethod
     def configure(
-        cls,
+        cls,  # type: typing.Type[APIPooled]
         max_workers=None,  # type: typing.Optional[int]
     ):  # type: (...) -> None
         """Pool executor create and configure.
@@ -63,7 +64,7 @@ def configure(
         raise NotImplementedError()  # pragma: no cover
 
     @classmethod
-    def shutdown(cls):  # type: () -> None
+    def shutdown(cls):  # type: (typing.Type[APIPooled]) -> None
         """Shutdown executor."""
         raise NotImplementedError()  # pragma: no cover
 
@@ -82,7 +83,7 @@ class BasePooled(APIPooled):
 
     @classmethod
     def configure(
-        cls,
+        cls,  # type: typing.Type[BasePooled]
         max_workers=None,  # type: typing.Optional[int]
     ):  # type: (...) -> None
         """Pool executor create and configure.
@@ -100,7 +101,7 @@ def configure(
         )
 
     @classmethod
-    def shutdown(cls):  # type: () -> None
+    def shutdown(cls):  # type: (typing.Type[BasePooled]) -> None
         """Shutdown executor."""
         if cls.__executor is not None:
             cls.__executor.shutdown()
diff --git a/threaded/_base_threaded.pyi b/threaded/_base_threaded.pyi
index 44c1496..f46c796 100644
--- a/threaded/_base_threaded.pyi
+++ b/threaded/_base_threaded.pyi
@@ -1,3 +1,4 @@
+import abc
 import concurrent.futures
 import threading
 import typing
@@ -5,22 +6,22 @@ from . import _class_decorator
 
 def cpu_count() -> int: ...
 
-class APIPooled(_class_decorator.BaseDecorator):
+class APIPooled(_class_decorator.BaseDecorator, metaclass=abc.ABCMeta):
     @classmethod
-    def configure(cls, max_workers: typing.Optional[int]=...) -> None: ...
+    def configure(cls: typing.Type[APIPooled], max_workers: typing.Optional[int]=...) -> None: ...
 
     @classmethod
-    def shutdown(cls) -> None: ...
+    def shutdown(cls: typing.Type[APIPooled]) -> None: ...
 
     @property
     def executor(self) -> typing.Any: ...
 
 class BasePooled(APIPooled):
     @classmethod
-    def configure(cls, max_workers: typing.Optional[int]=...) -> None: ...
+    def configure(cls: typing.Type[BasePooled], max_workers: typing.Optional[int]=...) -> None: ...
 
     @classmethod
-    def shutdown(cls) -> None: ...
+    def shutdown(cls: typing.Type[BasePooled]) -> None: ...
 
     @property
     def executor(self) -> ThreadPoolExecutor: ...
diff --git a/threaded/_class_decorator.py b/threaded/_class_decorator.py
index 6dadbe8..ac18778 100644
--- a/threaded/_class_decorator.py
+++ b/threaded/_class_decorator.py
@@ -21,13 +21,12 @@
 
 import abc
 import functools
-import sys
 import typing  # noqa  # pylint: disable=unused-import
 
-PY3 = sys.version_info[:2] > (3, 0)  # type: bool
+import six
 
 
-class BaseDecorator(object):
+class BaseDecorator(six.with_metaclass(abc.ABCMeta, object)):
     """Base class for decorators.
 
     Implements wrapping and __call__, wrapper getter is abstract.
@@ -81,7 +80,7 @@ def __init__(
         self.__func = func  # type: typing.Optional[typing.Callable]
         if self.__func is not None:
             functools.update_wrapper(self, self.__func)
-            if not PY3:  # pragma: no cover
+            if not six.PY3:  # pragma: no cover
                 self.__wrapped__ = self.__func  # type: typing.Callable
         # pylint: enable=assigning-non-slot
         # noinspection PyArgumentList
diff --git a/threaded/_class_decorator.pyi b/threaded/_class_decorator.pyi
index 0dc4410..fe35d2f 100644
--- a/threaded/_class_decorator.pyi
+++ b/threaded/_class_decorator.pyi
@@ -1,9 +1,8 @@
 import abc
 import typing
 
-PY3: bool
 
-class BaseDecorator:
+class BaseDecorator(object, metaclass=abc.ABCMeta):
     __wrapped__: typing.Optional[typing.Callable] = ...
     def __init__(self, func: typing.Optional[typing.Callable]=...) -> None: ...
 
diff --git a/threaded/_gthreadpooled2.py b/threaded/_gthreadpooled2.py
index 91ddd82..779ac6b 100644
--- a/threaded/_gthreadpooled2.py
+++ b/threaded/_gthreadpooled2.py
@@ -19,7 +19,7 @@
 
 from __future__ import absolute_import
 
-import typing
+import typing  # noqa  # pylint: disable=unused-import
 
 import gevent.event  # noqa  # pylint: disable=unused-import
 
@@ -37,24 +37,8 @@ class GThreadPooled(_base_gthreadpooled.BaseGThreadPooled):
     __slots__ = ()
 
 
-# pylint: disable=unused-argument, function-redefined
-@typing.overload
-def gthreadpooled(
-    func=None  # type: None
-):  # type: (...) -> GThreadPooled
-    """Post function to gevent.threadpool.ThreadPool."""
-
-
-@typing.overload  # noqa: F811
-def gthreadpooled(
-    func  # type: typing.Callable
-):  # type: (...) -> typing.Callable[..., gevent.event.AsyncResult]
-    """Post function to gevent.threadpool.ThreadPool."""
-# pylint: enable=unused-argument
-
-
 # pylint: disable=unexpected-keyword-arg, no-value-for-parameter
-def gthreadpooled(  # noqa: F811
+def gthreadpooled(
     func=None  # type: typing.Optional[typing.Callable]
 ):  # type: (...) -> typing.Union[GThreadPooled, typing.Callable[..., gevent.event.AsyncResult]]
     """Post function to gevent.threadpool.ThreadPool.
@@ -66,4 +50,4 @@ def gthreadpooled(  # noqa: F811
     if func is None:
         return GThreadPooled(func=func)
     return GThreadPooled(func=None)(func)
-# pylint: enable=unexpected-keyword-arg, no-value-for-parameter, function-redefined
+# pylint: enable=unexpected-keyword-arg, no-value-for-parameter
diff --git a/threaded/_gthreadpooled2.pyi b/threaded/_gthreadpooled2.pyi
index 1f05d4c..84d9427 100644
--- a/threaded/_gthreadpooled2.pyi
+++ b/threaded/_gthreadpooled2.pyi
@@ -4,4 +4,9 @@ from . import _base_gthreadpooled
 
 class GThreadPooled(_base_gthreadpooled.BaseGThreadPooled): ...
 
-def gthreadpooled(func: typing.Optional[typing.Callable]=...) -> typing.Union[GThreadPooled, typing.Callable[..., gevent.event.AsyncResult]]: ...
+
+@typing.overload
+def gthreadpooled(func: typing.Callable) -> typing.Callable[..., gevent.event.AsyncResult]: ...
+
+@typing.overload
+def gthreadpooled(func: None=...) -> GThreadPooled: ...
diff --git a/threaded/_gthreadpooled3.py b/threaded/_gthreadpooled3.py
index fa8ea37..1fad00d 100644
--- a/threaded/_gthreadpooled3.py
+++ b/threaded/_gthreadpooled3.py
@@ -64,24 +64,8 @@ def wrapper(
         return wrapper
 
 
-# pylint: disable=unused-argument, function-redefined
-@typing.overload
-def gthreadpooled(
-    func=None  # type: None
-):  # type: (...) -> GThreadPooled
-    """Post function to gevent.threadpool.ThreadPool."""
-
-
-@typing.overload  # noqa: F811
-def gthreadpooled(
-    func  # type: typing.Callable
-):  # type: (...) -> typing.Callable[..., gevent.event.AsyncResult]
-    """Post function to gevent.threadpool.ThreadPool."""
-# pylint: enable=unused-argument
-
-
 # pylint: disable=unexpected-keyword-arg, no-value-for-parameter
-def gthreadpooled(  # noqa: F811
+def gthreadpooled(
     func: typing.Optional[typing.Callable] = None
 ) -> typing.Union[GThreadPooled, typing.Callable[..., gevent.event.AsyncResult]]:
     """Post function to gevent.threadpool.ThreadPool.
@@ -93,4 +77,4 @@ def gthreadpooled(  # noqa: F811
     if func is None:
         return GThreadPooled(func=func)
     return GThreadPooled(func=None)(func)
-# pylint: enable=unexpected-keyword-arg, no-value-for-parameter, function-redefined
+# pylint: enable=unexpected-keyword-arg, no-value-for-parameter
diff --git a/threaded/_gthreadpooled3.pyi b/threaded/_gthreadpooled3.pyi
index 1f05d4c..84d9427 100644
--- a/threaded/_gthreadpooled3.pyi
+++ b/threaded/_gthreadpooled3.pyi
@@ -4,4 +4,9 @@ from . import _base_gthreadpooled
 
 class GThreadPooled(_base_gthreadpooled.BaseGThreadPooled): ...
 
-def gthreadpooled(func: typing.Optional[typing.Callable]=...) -> typing.Union[GThreadPooled, typing.Callable[..., gevent.event.AsyncResult]]: ...
+
+@typing.overload
+def gthreadpooled(func: typing.Callable) -> typing.Callable[..., gevent.event.AsyncResult]: ...
+
+@typing.overload
+def gthreadpooled(func: None=...) -> GThreadPooled: ...
diff --git a/threaded/_py3_helpers.py b/threaded/_py3_helpers.py
index 1ca4f56..0b741aa 100644
--- a/threaded/_py3_helpers.py
+++ b/threaded/_py3_helpers.py
@@ -25,8 +25,8 @@
 
 
 def get_loop(
-        self,
-        *args, **kwargs
+        self: typing.Any,
+        *args: typing.Tuple, **kwargs: typing.Dict
 ) -> typing.Optional[asyncio.AbstractEventLoop]:
     """Get event loop in decorator class."""
     if callable(self.loop_getter):
diff --git a/threaded/_py3_helpers.pyi b/threaded/_py3_helpers.pyi
index c4537dc..9262a45 100644
--- a/threaded/_py3_helpers.pyi
+++ b/threaded/_py3_helpers.pyi
@@ -1,5 +1,5 @@
 import asyncio
 import typing
 
-def get_loop(self, *args, **kwargs) -> typing.Optional[asyncio.AbstractEventLoop]: ...
+def get_loop(self: typing.Any, *args: typing.Tuple, **kwargs: typing.Dict) -> typing.Optional[asyncio.AbstractEventLoop]: ...
 def await_if_required(target: typing.Callable) -> typing.Callable[..., typing.Any]: ...
diff --git a/threaded/_threaded2.py b/threaded/_threaded2.py
index ef441a6..ec3d58d 100644
--- a/threaded/_threaded2.py
+++ b/threaded/_threaded2.py
@@ -21,7 +21,7 @@
 
 import concurrent.futures  # noqa  # pylint: disable=unused-import
 import threading  # noqa  # pylint: disable=unused-import
-import typing
+import typing  # noqa  # pylint: disable=unused-import
 
 from . import _base_threaded
 
@@ -45,24 +45,8 @@ class Threaded(_base_threaded.BaseThreaded):
     __slots__ = ()
 
 
-# pylint: disable=unused-argument, function-redefined
-@typing.overload
-def threadpooled(
-    func=None  # type: None
-):  # type: (...) -> ThreadPooled
-    """Post function to ThreadPoolExecutor."""
-
-
-@typing.overload  # noqa: F811
-def threadpooled(
-    func  # type: typing.Callable
-):  # type: (...) -> typing.Callable[..., concurrent.futures.Future]
-    """Post function to ThreadPoolExecutor."""
-# pylint: enable=unused-argument
-
-
 # pylint: disable=unexpected-keyword-arg, no-value-for-parameter
-def threadpooled(  # noqa: F811
+def threadpooled(
     func=None  # type: typing.Optional[typing.Callable]
 ):  # type: (...) -> typing.Union[ThreadPooled, typing.Callable[..., concurrent.futures.Future]]
     """Post function to ThreadPoolExecutor.
@@ -76,27 +60,7 @@ def threadpooled(  # noqa: F811
     return ThreadPooled(func=None)(func)
 
 
-# pylint: disable=unused-argument
-@typing.overload
-def threaded(
-    name=None,  # type: typing.Optional[str]
-    daemon=False,  # type: bool
-    started=False  # type: bool
-):  # type: (...) -> Threaded
-    """Run function in separate thread."""
-
-
-@typing.overload  # noqa: F811
 def threaded(
-    name,  # type: typing.Callable
-    daemon=False,  # type: bool
-    started=False  # type: bool
-):  # type: (...) -> typing.Callable[..., threading.Thread]
-    """Run function in separate thread."""
-# pylint: enable=unused-argument
-
-
-def threaded(  # noqa: F811
     name=None,  # type: typing.Optional[typing.Union[str, typing.Callable]]
     daemon=False,  # type: bool
     started=False  # type: bool
@@ -120,4 +84,4 @@ def threaded(  # noqa: F811
         )
         return Threaded(name=name, daemon=daemon, started=started)(func)
     return Threaded(name=name, daemon=daemon, started=started)
-# pylint: enable=unexpected-keyword-arg, no-value-for-parameter, function-redefined
+# pylint: enable=unexpected-keyword-arg, no-value-for-parameter
diff --git a/threaded/_threaded2.pyi b/threaded/_threaded2.pyi
index 2a1b3f3..cd52769 100644
--- a/threaded/_threaded2.pyi
+++ b/threaded/_threaded2.pyi
@@ -6,10 +6,18 @@ from . import _base_threaded
 class ThreadPooled(_base_threaded.BasePooled): ...
 class Threaded(_base_threaded.BaseThreaded): ...
 
-def threadpooled(func: typing.Optional[typing.Callable]=...) -> typing.Union[ThreadPooled, typing.Callable[..., concurrent.futures.Future]]: ...
 
-def threaded(
-    name: typing.Optional[typing.Union[str, typing.Callable]]=...,
-    daemon: bool=...,
-    started: bool=...
-) -> typing.Union[Threaded, typing.Callable[..., threading.Thread]]: ...
+
+
+@typing.overload
+def threadpooled(func: typing.Callable) -> typing.Callable[..., concurrent.futures.Future]: ...
+
+@typing.overload
+def threadpooled(func: None=...) -> ThreadPooled: ...
+
+
+@typing.overload
+def threaded(name: typing.Callable, daemon: bool=..., started: bool=...) -> typing.Callable[..., threading.Thread]: ...
+
+@typing.overload
+def threaded(name: typing.Optional[str]=..., daemon: bool=..., started: bool=...) -> Threaded: ...
diff --git a/threaded/_threaded3.py b/threaded/_threaded3.py
index 1eb59bb..5e60811 100644
--- a/threaded/_threaded3.py
+++ b/threaded/_threaded3.py
@@ -309,49 +309,8 @@ def __repr__(self):
         )  # pragma: no cover
 
 
-# pylint: disable=unused-argument, function-redefined
-@typing.overload
-def threadpooled(
-    func: None = None,
-    *,
-    loop_getter: typing.Union[
-        None,
-        typing.Callable[..., asyncio.AbstractEventLoop],
-        asyncio.AbstractEventLoop
-    ]=None,
-    loop_getter_need_context: bool = False
-) -> ThreadPooled:
-    """Post function to ThreadPoolExecutor."""
-
-
-@typing.overload  # noqa: F811
-def threadpooled(
-    func: typing.Callable,
-    *,
-    loop_getter: None = None,
-    loop_getter_need_context: bool = False
-
-) -> typing.Callable[..., concurrent.futures.Future]:
-    """Post function to ThreadPoolExecutor."""
-
-
-@typing.overload  # noqa: F811
-def threadpooled(
-    func: typing.Callable,
-    *,
-    loop_getter: typing.Union[
-        typing.Callable[..., asyncio.AbstractEventLoop],
-        asyncio.AbstractEventLoop
-    ],
-    loop_getter_need_context: bool = False
-
-) -> typing.Callable[..., asyncio.Task]:
-    """Post function to ThreadPoolExecutor."""
-# pylint: enable=unused-argument
-
-
 # pylint: disable=unexpected-keyword-arg, no-value-for-parameter
-def threadpooled(  # noqa: F811
+def threadpooled(
     func: typing.Optional[typing.Callable] = None,
     *,
     loop_getter: typing.Union[
@@ -388,27 +347,7 @@ def threadpooled(  # noqa: F811
     )(func)
 
 
-# pylint: disable=unused-argument
-@typing.overload
 def threaded(
-    name: typing.Optional[str] = None,
-    daemon: bool = False,
-    started: bool = False
-):  # type: (...) -> Threaded
-    """Run function in separate thread."""
-
-
-@typing.overload  # noqa: F811
-def threaded(
-    name: typing.Callable,
-    daemon: bool = False,
-    started: bool = False
-) -> typing.Callable[..., threading.Thread]:
-    """Run function in separate thread."""
-# pylint: enable=unused-argument
-
-
-def threaded(  # noqa: F811
     name: typing.Optional[typing.Union[str, typing.Callable]] = None,
     daemon: bool = False,
     started: bool = False
@@ -434,35 +373,7 @@ def threaded(  # noqa: F811
     return Threaded(name=name, daemon=daemon, started=started)
 
 
-# pylint: disable=unused-argument
-@typing.overload
-def asynciotask(
-    func=None,
-    *,
-    loop_getter: typing.Union[
-        typing.Callable[..., asyncio.AbstractEventLoop],
-        asyncio.AbstractEventLoop
-    ]=asyncio.get_event_loop,
-    loop_getter_need_context: bool = False
-) -> AsyncIOTask:
-    """Wrap function in future and return."""
-
-
-@typing.overload  # noqa: F811
 def asynciotask(
-    func: typing.Callable,
-    *,
-    loop_getter: typing.Union[
-        typing.Callable[..., asyncio.AbstractEventLoop],
-        asyncio.AbstractEventLoop
-    ]=asyncio.get_event_loop,
-    loop_getter_need_context: bool = False
-) -> typing.Callable[..., asyncio.Task]:
-    """Wrap function in future and return."""
-# pylint: enable=unused-argument
-
-
-def asynciotask(  # noqa: F811
     func: typing.Optional[typing.Callable] = None,
     *,
     loop_getter: typing.Union[
@@ -495,4 +406,4 @@ def asynciotask(  # noqa: F811
         loop_getter=loop_getter,
         loop_getter_need_context=loop_getter_need_context
     )(func)
-# pylint: enable=unexpected-keyword-arg, no-value-for-parameter, function-redefined
+# pylint: enable=unexpected-keyword-arg, no-value-for-parameter
diff --git a/threaded/_threaded3.pyi b/threaded/_threaded3.pyi
index 7853302..12c7f6f 100644
--- a/threaded/_threaded3.pyi
+++ b/threaded/_threaded3.pyi
@@ -41,22 +41,66 @@ class AsyncIOTask(_class_decorator.BaseDecorator):
 
     def _get_function_wrapper(self, func: typing.Callable) -> typing.Callable[..., asyncio.Task]: ...
 
+
+@typing.overload
+def threadpooled(
+    func: typing.Callable,
+    *,
+    loop_getter: None = ...,
+    loop_getter_need_context: bool = ...
+
+) -> typing.Callable[..., concurrent.futures.Future]: ...
+
+@typing.overload
 def threadpooled(
-    func: typing.Optional[typing.Callable]=...,
+    func: typing.Callable,
     *,
-    loop_getter: typing.Union[None, typing.Callable[..., asyncio.AbstractEventLoop], asyncio.AbstractEventLoop]=...,
-    loop_getter_need_context: bool=...
-) -> typing.Union[ThreadPooled, typing.Callable[..., typing.Union[concurrent.futures.Future, asyncio.Task]]]: ...
+    loop_getter: typing.Union[
+        typing.Callable[..., asyncio.AbstractEventLoop],
+        asyncio.AbstractEventLoop
+    ],
+    loop_getter_need_context: bool = ...
+
+) -> typing.Callable[..., asyncio.Task]: ...
 
-def threaded(
-    name: typing.Optional[typing.Union[str, typing.Callable]]=...,
-    daemon: bool=...,
-    started: bool=...
-) -> typing.Union[Threaded, typing.Callable[..., threading.Thread]]: ...
+@typing.overload
+def threadpooled(
+    func: None = ...,
+    *,
+    loop_getter: typing.Union[
+        None,
+        typing.Callable[..., asyncio.AbstractEventLoop],
+        asyncio.AbstractEventLoop
+    ]=...,
+    loop_getter_need_context: bool = ...
+) -> ThreadPooled: ...
+
+
+@typing.overload
+def threaded(name: typing.Callable, daemon: bool = ..., started: bool = ...) -> typing.Callable[..., threading.Thread]: ...
+
+@typing.overload
+def threaded(name: typing.Optional[str] = ..., daemon: bool = ..., started: bool = ...) -> Threaded: ...
+
+
+@typing.overload
+def asynciotask(
+    func: None= ...,
+    *,
+    loop_getter: typing.Union[
+        typing.Callable[..., asyncio.AbstractEventLoop],
+        asyncio.AbstractEventLoop
+    ]=asyncio.get_event_loop,
+    loop_getter_need_context: bool = ...
+) -> AsyncIOTask: ...
 
+@typing.overload
 def asynciotask(
-    func: typing.Optional[typing.Callable]=...,
+    func: typing.Callable,
     *,
-    loop_getter: typing.Union[typing.Callable[..., asyncio.AbstractEventLoop], asyncio.AbstractEventLoop]=...,
-    loop_getter_need_context: bool=...
-) -> typing.Union[AsyncIOTask, typing.Callable[..., asyncio.Task]]: ...
+    loop_getter: typing.Union[
+        typing.Callable[..., asyncio.AbstractEventLoop],
+        asyncio.AbstractEventLoop
+    ]=asyncio.get_event_loop,
+    loop_getter_need_context: bool = ...
+) -> typing.Callable[..., asyncio.Task]: ...
diff --git a/tox.ini b/tox.ini
index 300cdb4..9ada10a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -86,7 +86,7 @@ commands = pip install ./ -vvv -U
 
 [testenv:pylint]
 deps =
-    pylint
+    pylint < 2.0
     -r{toxinidir}/CI_REQUIREMENTS.txt
 commands = pylint threaded
 
@@ -129,3 +129,9 @@ deps =
     .[gevent]
     pipdeptree
 commands = pipdeptree
+
+[testenv:mypy]
+deps =
+    mypy>=0.620
+    -r{toxinidir}/CI_REQUIREMENTS.txt
+commands = mypy --strict threaded