diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a00563..dd06ddc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Changed
+
+- Python 3.9+ is required [#152](https://github.com/python-backoff/backoff/pull/152)
+
 ### Documentation
 
 - Fixed some examples [#116](https://github.com/python-backoff/backoff/pull/116) (from [@edgarrmondragon](https://github.com/edgarrmondragon))
diff --git a/backoff/_decorator.py b/backoff/_decorator.py
index 3be55f6..d8b4c75 100644
--- a/backoff/_decorator.py
+++ b/backoff/_decorator.py
@@ -3,7 +3,7 @@
 import inspect
 import logging
 import operator
-from typing import TYPE_CHECKING, Any, Callable, Iterable
+from typing import TYPE_CHECKING, Any, Callable
 
 from backoff import _async, _sync
 from backoff._common import (
@@ -15,6 +15,8 @@
 from backoff._jitter import full_jitter
 
 if TYPE_CHECKING:
+    from collections.abc import Iterable
+
     from backoff._typing import (
         _CallableT,
         _Handler,
diff --git a/backoff/_typing.py b/backoff/_typing.py
index c2b42ad..5485604 100644
--- a/backoff/_typing.py
+++ b/backoff/_typing.py
@@ -1,13 +1,11 @@
 from __future__ import annotations
 
 import logging
+from collections.abc import Coroutine, Generator, Sequence
 from typing import (
     TYPE_CHECKING,
     Any,
     Callable,
-    Coroutine,
-    Generator,
-    Sequence,
     TypedDict,
     TypeVar,
     Union,
diff --git a/backoff/_wait_gen.py b/backoff/_wait_gen.py
index f015989..ec904dd 100644
--- a/backoff/_wait_gen.py
+++ b/backoff/_wait_gen.py
@@ -2,7 +2,10 @@
 
 import itertools
 import math
-from typing import Any, Callable, Generator, Iterable
+from typing import TYPE_CHECKING, Any, Callable
+
+if TYPE_CHECKING:
+    from collections.abc import Generator, Iterable
 
 
 def expo(
diff --git a/pyproject.toml b/pyproject.toml
index d16ae86..1f3b2e7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ version = "2.3.1"
 description = "Function decoration for backoff and retry"
 authors = [{ name = "Bob Green", email = "rgreen@aquent.com" }]
 maintainers = [{ name = "Edgar Ramírez-Mondragón", email = "edgarrm358@gmail.com" }]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 readme = "README.rst"
 license = "MIT"
 keywords = [
@@ -19,7 +19,6 @@ classifiers = [
     "Operating System :: OS Independent",
     "Programming Language :: Python",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
@@ -73,12 +72,11 @@ include = ["backoff", "tests"]
 include = ["backoff"]
 
 [tool.tox]
-min_version = "4.43"
-requires = [ "tox>=4.43", "tox-uv" ]
+requires = [ "tox>=4.53", "tox-uv" ]
 env_list = [
   "format",
   { product = [
-    { prefix = "3.", start = 8 },
+    { prefix = "3.", start = 9 },
   ] },
   "coverage",
   "lint",
@@ -87,7 +85,7 @@ env_list = [
 ]
 
 [tool.tox.env_run_base]
-description = "run unit tests"
+description = "run unit tests on Python {py_dot_ver}"
 dependency_groups = [ "test" ]
 uv_python_preference = "managed"
 commands = [
diff --git a/tests/test_backoff.py b/tests/test_backoff.py
index 2aac96a..6a56a61 100644
--- a/tests/test_backoff.py
+++ b/tests/test_backoff.py
@@ -928,9 +928,12 @@ def test_event_log_levels(
     max_tries = 3
     func = func_factory(backoff_log_level, giveup_log_level, max_tries)
 
-    with unittest.mock.patch("time.sleep", return_value=None), caplog.at_level(
-        min(backoff_log_level, giveup_log_level),
-        logger="backoff",
+    with (
+        unittest.mock.patch("time.sleep", return_value=None),
+        caplog.at_level(
+            min(backoff_log_level, giveup_log_level),
+            logger="backoff",
+        ),
     ):
         func()