diff --git a/.github/workflows/format.yml b/.github/workflows/format.yml
index 554c5ed..9f95936 100644
--- a/.github/workflows/format.yml
+++ b/.github/workflows/format.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
     - name: Setup Node.js
       uses: actions/setup-node@v7
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index d2fc89f..7f6e161 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
     - name: Setup Node.js
       uses: actions/setup-node@v7
diff --git a/.github/workflows/typecheck.yml b/.github/workflows/typecheck.yml
index 6513703..abd1d70 100644
--- a/.github/workflows/typecheck.yml
+++ b/.github/workflows/typecheck.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v7
+    - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
 
     - name: Setup Node.js
       uses: actions/setup-node@v7