diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index fa073ba..9e08f05 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
     - name: Set up cache
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index c87b9b3..7ab7b78 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -9,7 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
     - name: Setup Rubygems