diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 84c9dc5..df5e761 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -23,7 +23,6 @@ jobs:
           - "3.12"
           - "3.11"
           - "3.10"
-          - "3.9"
         os: [windows-latest, macos-latest, ubuntu-latest]
 
     steps:
diff --git a/pyproject.toml b/pyproject.toml
index d332764..bdfa940 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,14 +16,13 @@ license = "MIT"
 license-files = [ "LICENCE" ]
 maintainers = [ { name = "Hugo van Kemenade" } ]
 authors = [ { name = "Jason Moiron", email = "jmoiron@jmoiron.net" } ]
-requires-python = ">=3.9"
+requires-python = ">=3.10"
 classifiers = [
   "Development Status :: 5 - Production/Stable",
   "Intended Audience :: Developers",
   "Operating System :: OS Independent",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3 :: Only",
-  "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
diff --git a/src/humanize/number.py b/src/humanize/number.py
index 5154895..8126e35 100644
--- a/src/humanize/number.py
+++ b/src/humanize/number.py
@@ -9,12 +9,7 @@
 
 TYPE_CHECKING = False
 if TYPE_CHECKING:
-    import sys
-
-    if sys.version_info >= (3, 10):
-        from typing import TypeAlias
-    else:
-        from typing_extensions import TypeAlias
+    from typing import TypeAlias
 
     # This type can be better defined by typing.SupportsFloat
     # but that's a Python 3.8 only typing option.
diff --git a/tox.ini b/tox.ini
index bb7e6c1..55687a4 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@ env_list =
     docs
     lint
     mypy
-    py{py3, 314, 313, 312, 311, 310, 39}
+    py{py3, 314, 313, 312, 311, 310}
 
 [testenv]
 extras =