diff --git a/.github/workflows/ci-pr.yml b/.github/workflows/ci-pr.yml
index f5d70e44..7681fd0f 100644
--- a/.github/workflows/ci-pr.yml
+++ b/.github/workflows/ci-pr.yml
@@ -30,7 +30,7 @@ jobs:
 
     steps:
       - name: Checkout PR branch into cwd
-        uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+        uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           # Checkout the fork/head-repository to push changes to the fork.
           # Without this the base repository will be checked out and committed to.
@@ -40,7 +40,7 @@ jobs:
           ref: ${{ github.head_ref }}
 
       - name: Checkout main branch into directory _main_branch/
-        uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+        uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           ref: main
           path: _main_branch
diff --git a/.github/workflows/merge.yml b/.github/workflows/merge.yml
index 8401bbe2..4588a677 100644
--- a/.github/workflows/merge.yml
+++ b/.github/workflows/merge.yml
@@ -31,13 +31,13 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+      - uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           # Using fetch-depth 0 is the only way to get all tags which are needed for building docs.
           fetch-depth: 0
 
       - name: Checkout gh-pages branch to dir publish/
-        uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+        uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           ref: gh-pages
           path: publish
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 529c7548..ef1c4f6d 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -31,13 +31,13 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+      - uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           # Using fetch-depth 0 is the only way to get all tags which are needed for building docs.
           fetch-depth: 0
 
       - name: Checkout gh-pages branch to dir publish/
-        uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
+        uses: actions/checkout@eef61447b9ff4aafe5dcd4e0bbf5d482be7e7871
         with:
           ref: gh-pages
           path: publish