diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 878934d..81b7b80 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -5,8 +5,8 @@ jobs:
   build-sdist:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-python@v4
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
         with:
           python-version: "3.10"
           cache: "pip"
@@ -14,7 +14,7 @@ jobs:
         run: |
           pip install -r requirements.txt
           python -m build -s
-      - uses: actions/upload-artifact@v3
+      - uses: actions/upload-artifact@v4
         with:
           name: sdist
           path: dist
@@ -27,16 +27,16 @@ jobs:
     name: Build wheels on ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
 
       - name: Set up QEMU
         if: runner.os == 'Linux'
-        uses: docker/setup-qemu-action@v2
+        uses: docker/setup-qemu-action@v3
         with:
           platforms: arm64
 
       - name: Set up Python 3.10
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
           python-version: "3.10"
           cache: "pip"
@@ -48,14 +48,25 @@ jobs:
           python -m build -s  # to run Cythonize
 
       - name: Build
-        uses: pypa/cibuildwheel@v2.15.0
+        uses: pypa/cibuildwheel@v2.21.2
         env:
           CIBW_ARCHS_LINUX: auto aarch64
           CIBW_ARCHS_MACOS: x86_64 universal2 arm64
           CIBW_SKIP: pp*
 
       - name: Upload Wheels to artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
-          name: Wheels
+          name: Wheels-${{ matrix.os }}
           path: wheelhouse
+
+  merge:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Merge Artifacts
+        uses: actions/upload-artifact/merge@v4
+        with:
+          name: Wheels
+          pattern: Wheels-*
+          delete-merged: true
diff --git a/setup.cfg b/setup.cfg
index 6e62c94..1348f82 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,13 +1,13 @@
 [metadata]
 name = wsaccel
 version = 0.6.6
-requires-python = >=3.9
+requires_python = >=3.9
 description = Accelerator for ws4py and AutobahnPython
 maintainer = Inada Naoki
 maintainer_email = songofacandy@gmail.com
 url = https://github.com/methane/wsaccel
 license = Apache 2.0
-long_description = file: README.md
+long_description = file: README.rst
 long_description_content_type = text/x-rst
 classifiers=
     Intended Audience :: Developers
@@ -18,4 +18,5 @@ classifiers=
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
     Programming Language :: Python :: 3.12
+    Programming Language :: Python :: 3.13
     Programming Language :: Python :: Implementation :: CPython
diff --git a/wsaccel/utf8validator.pyx b/wsaccel/utf8validator.pyx
index 0d6074c..6c002da 100644
--- a/wsaccel/utf8validator.pyx
+++ b/wsaccel/utf8validator.pyx
@@ -1,3 +1,4 @@
+# cython: language_level=3
 # coding=utf-8
 
 ###############################################################################
diff --git a/wsaccel/xormask.pyx b/wsaccel/xormask.pyx
index 47127f9..5c175d6 100644
--- a/wsaccel/xormask.pyx
+++ b/wsaccel/xormask.pyx
@@ -1,3 +1,4 @@
+# cython: language_level=3
 from cpython.buffer cimport *
 from cpython.bytes cimport *