diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 849d245..1f6376a 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,7 +10,7 @@ jobs:
         arch: [x86_64, aarch64]
     runs-on: ${{ case(matrix.arch == 'x86_64', 'ubuntu-latest', 'ubuntu-22.04-arm') }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: actions/cache/restore@v5
       with:
         path: download
@@ -33,7 +33,7 @@ jobs:
         arch: [x86_64, aarch64]
     runs-on: ${{ case(matrix.arch == 'x86_64', 'ubuntu-latest', 'ubuntu-22.04-arm') }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: actions/cache/restore@v5
       with:
         path: download
@@ -61,7 +61,7 @@ jobs:
         build: [x86_64, arm64]
     runs-on: ${{ case(matrix.arch == 'x86_64', 'macos-15-intel', 'macos-14') }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: actions/cache/restore@v5
       with:
         path: download
diff --git a/.github/workflows/cache-downloads.yml b/.github/workflows/cache-downloads.yml
index 30e3400..e69792f 100644
--- a/.github/workflows/cache-downloads.yml
+++ b/.github/workflows/cache-downloads.yml
@@ -12,7 +12,7 @@ jobs:
   cache-downloads:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: '4'
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 9842e0e..b6e8700 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -24,7 +24,7 @@ jobs:
         - jruby-10.1
       fail-fast: false
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: "${{ matrix.ruby }}"
diff --git a/.github/workflows/docker-build.yml b/.github/workflows/docker-build.yml
index 1a9aff5..e3196fe 100644
--- a/.github/workflows/docker-build.yml
+++ b/.github/workflows/docker-build.yml
@@ -13,7 +13,7 @@ jobs:
         - DOCKER_FILE=Dockerfile.debian DOCKER_TAG_SUFFIX=-debian
       fail-fast: false
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: actions/cache/restore@v5
       with:
         path: download
diff --git a/.github/workflows/livecheck.yml b/.github/workflows/livecheck.yml
index 702f1ab..b860d4c 100644
--- a/.github/workflows/livecheck.yml
+++ b/.github/workflows/livecheck.yml
@@ -14,7 +14,7 @@ jobs:
   livecheck:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: '4'
diff --git a/.github/workflows/rubocop.yml b/.github/workflows/rubocop.yml
index c74c1ea..76f33e9 100644
--- a/.github/workflows/rubocop.yml
+++ b/.github/workflows/rubocop.yml
@@ -8,7 +8,7 @@ jobs:
   rubocop:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@v6.0.3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: '4'