diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index db49997..e787ec4 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -25,11 +25,11 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           fetch-depth: 0
 
-      - uses: hynek/build-and-inspect-python-package@v2
+      - uses: hynek/build-and-inspect-python-package@c52c3a4710070b50470d903818a7b25115dcd076 # v2.13.0
 
   test-publish:
     needs: [dist]
@@ -42,12 +42,12 @@ jobs:
     if: github.event_name == 'release' && github.event.action == 'published'
 
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
         with:
           name: Packages
           path: dist
 
-      - uses: pypa/gh-action-pypi-publish@release/v1
+      - uses: pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc # v1.12.4
         if: github.event_name == 'release' && github.event.action == 'published'
         with:
           # Remember to tell (test-)pypi about this repo before publishing
@@ -64,9 +64,9 @@ jobs:
     if: github.event_name == 'release' && github.event.action == 'published'
 
     steps:
-      - uses: actions/download-artifact@v4
+      - uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
         with:
           name: Packages
           path: dist
 
-      - uses: pypa/gh-action-pypi-publish@release/v1
+      - uses: pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc # v1.12.4
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a5d9943..f41a39c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,10 +21,8 @@ jobs:
     name: Format
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: "3.x"
       # - uses: pre-commit/action@v3.0.1
@@ -44,11 +42,8 @@ jobs:
         runs-on: [ubuntu-latest, windows-latest, macos-latest]
 
     steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
-
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5.6.0
         with:
           python-version: ${{ matrix.python-version }}
           allow-prereleases: true
@@ -62,6 +57,6 @@ jobs:
           --durations=20
 
       - name: Upload coverage report
-        uses: codecov/codecov-action@v5.4.3
+        uses: codecov/codecov-action@fdcc8476540edceab3de004e990f80d881c6cc00 # v5.5.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}