diff --git a/.github/workflows/php-tests.yml b/.github/workflows/php-tests.yml
index f39621f..324dbc4 100644
--- a/.github/workflows/php-tests.yml
+++ b/.github/workflows/php-tests.yml
@@ -37,7 +37,7 @@ jobs:
                 run: "composer validate --ansi --strict"
 
             -   name: "Determine composer cache directory"
-                uses: "ergebnis/.github/actions/composer/determine-cache-directory@1.9.3"
+                uses: "ergebnis/.github/actions/composer/determine-cache-directory@b7a813b437712bae6ea583a4071c631d2d8bee6d" # 1.9.3
 
             -   name: "Cache dependencies installed with composer"
                 uses: "actions/cache@0400d5f644dc74513175e3cd8d07132dd4860809" # v4.2.4
@@ -47,7 +47,7 @@ jobs:
                     restore-keys: "php-${{ matrix.php-version }}-composer-${{ matrix.dependencies }}-"
 
             -   name: "Install ${{ matrix.dependencies }} dependencies with composer"
-                uses: "ergebnis/.github/actions/composer/install@1.9.3"
+                uses: "ergebnis/.github/actions/composer/install@b7a813b437712bae6ea583a4071c631d2d8bee6d" # 1.9.3
                 with:
                     dependencies: "${{ matrix.dependencies }}"
 
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 02372da..948c337 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -19,9 +19,9 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@08eba0b27e820071cde6df949e0beb9ba4906955 # v4
       - name: Semantic Release
-        uses: cycjimmy/semantic-release-action@v4.2.2
+        uses: cycjimmy/semantic-release-action@16ca923e6ccbb50770c415a0ccd43709a8c5f7a4 # v4.2.2
         with:
           tag_format: ${version}
           branches: |