diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -10,21 +10,19 @@ jobs:
    strategy:
      matrix:
        os: ["ubuntu-latest", "windows-latest", "windows-11-arm", "macos-latest"]
-        py: ["3.14", "3.14t", "3.13", "3.12", "3.11", "3.10", "3.9"]
        exclude:
-          - os: windows-11-arm
-            py: "3.9"
          - os: windows-11-arm
            py: "3.10"
    runs-on: ${{ matrix.os }}
    name: Run test with Python ${{ matrix.py }} on ${{ matrix.os }}

    steps:
      - name: Checkout
-        uses: actions/checkout@v4

      - name: Set up Python
-        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.py }}
          allow-prereleases: true

diff --git a/.github/workflows/wheel.yml b/.github/workflows/wheel.yml
@@ -17,8 +17,8 @@ jobs:
    name: Build wheels on ${{ matrix.os }}

    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
        with:
          python-version: "3.x"
          cache: "pip"
@@ -33,7 +33,7 @@ jobs:
        env:
          CIBW_TEST_REQUIRES: "pytest"
          CIBW_TEST_COMMAND: "pytest {package}/test"
-          CIBW_SKIP: "pp* cp38-* cp39-win_arm64 cp310-win_arm64"

      - name: Build sdist
        if: runner.os == 'Linux' && runner.arch == 'X64'

diff --git a/pyproject.toml b/pyproject.toml
@@ -10,7 +10,7 @@ authors = [{name="Inada Naoki", email="songofacandy@gmail.com"}]
description = "MessagePack serializer"
readme = "README.md"
keywords = ["msgpack", "messagepack", "serializer", "serialization", "binary"]
-requires-python = ">=3.9"
classifiers = [
    "Development Status :: 5 - Production/Stable",
    "Operating System :: OS Independent",
@@ -36,7 +36,7 @@ version = {attr = "msgpack.__version__"}

[tool.ruff]
line-length = 100
-target-version = "py39"
lint.select = [
    "E", # pycodestyle
    "F", # Pyflakes