diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index e071463..8b9e1e6 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -23,9 +23,9 @@ jobs:
         python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
 
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v6
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405  # v6.2.0
       with:
         python-version: ${{ matrix.python-version }}
         allow-prereleases: true
@@ -41,9 +41,9 @@ jobs:
 
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
     - name: Use Node.js 15
-      uses: actions/setup-node@v6.3.0
+      uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e  # v6.4.0
       with:
         node-version: '15'
     - name: Install jest
@@ -59,9 +59,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout source
-      uses: actions/checkout@v6
+      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10  # v6.0.3
     - name: Set up Python 3.12
-      uses: actions/setup-python@v6
+      uses: actions/setup-python@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e  # v6.4.0
       with:
         python-version: 3.12
     - name: Build package
@@ -69,7 +69,7 @@ jobs:
         python -m pip install -U pip build
         python -m build --sdist --wheel .
     - name: Publish
-      uses: pypa/gh-action-pypi-publish@v1.14.0
+      uses: pypa/gh-action-pypi-publish@cef221092ed1bacb1cc03d23a2d87d1d172e277b  # v1.14.0
       with:
         user: __token__
         password: ${{ secrets.PYPI_KEY }}