diff --git a/fastapi/concurrency.py b/fastapi/concurrency.py
index becac3f33db76..e3dd11dbbb550 100644
--- a/fastapi/concurrency.py
+++ b/fastapi/concurrency.py
@@ -1,4 +1,5 @@
-import sys
+from contextlib import AsyncExitStack as AsyncExitStack  # noqa
+from contextlib import asynccontextmanager as asynccontextmanager
 from typing import AsyncGenerator, ContextManager, TypeVar
 
 from starlette.concurrency import iterate_in_threadpool as iterate_in_threadpool  # noqa
@@ -7,14 +8,6 @@
     run_until_first_complete as run_until_first_complete,
 )
 
-if sys.version_info >= (3, 7):
-    from contextlib import AsyncExitStack as AsyncExitStack
-    from contextlib import asynccontextmanager as asynccontextmanager
-else:
-    from contextlib2 import AsyncExitStack as AsyncExitStack  # noqa
-    from contextlib2 import asynccontextmanager as asynccontextmanager  # noqa
-
-
 _T = TypeVar("_T")
 
 
diff --git a/pyproject.toml b/pyproject.toml
index 3ae0085770838..2a9d62ddb38ef 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -70,7 +70,6 @@ test = [
     # types
     "types-ujson ==4.2.1",
     "types-orjson ==3.6.2",
-    "types-dataclasses ==0.6.5; python_version<'3.7'",
 ]
 doc = [
     "mkdocs >=1.1.2,<2.0.0",