diff --git a/.github/workflows/vouch-issue-comment.yml b/.github/workflows/vouch-issue-comment.yml
index d97529ebd..312e58e36 100644
--- a/.github/workflows/vouch-issue-comment.yml
+++ b/.github/workflows/vouch-issue-comment.yml
@@ -13,7 +13,7 @@ jobs:
       issues: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           ref: ${{ github.event.repository.default_branch }}
 
diff --git a/.github/workflows/vouch-pr-comment.yml b/.github/workflows/vouch-pr-comment.yml
index 3fe66e148..82eafc3c9 100644
--- a/.github/workflows/vouch-pr-comment.yml
+++ b/.github/workflows/vouch-pr-comment.yml
@@ -13,7 +13,7 @@ jobs:
       pull-requests: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           ref: ${{ github.event.repository.default_branch }}
 
diff --git a/.github/workflows/vouch-pr-gate.yml b/.github/workflows/vouch-pr-gate.yml
index c86207248..5bedc0906 100644
--- a/.github/workflows/vouch-pr-gate.yml
+++ b/.github/workflows/vouch-pr-gate.yml
@@ -13,7 +13,7 @@ jobs:
       pull-requests: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           ref: ${{ github.event.repository.default_branch }}