diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 2106ab60..e2e9e86a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -37,7 +37,7 @@ jobs:
             python-version: "3.13"
             os: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set environment variables
@@ -88,7 +88,7 @@ jobs:
       matrix:
         python-version: ["3.11", "3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set up conda environment
diff --git a/.github/workflows/pypi.yaml b/.github/workflows/pypi.yaml
index 72ba1d51..0a78e070 100644
--- a/.github/workflows/pypi.yaml
+++ b/.github/workflows/pypi.yaml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository == 'xarray-contrib/cf-xarray'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       - uses: actions/setup-python@v5
diff --git a/.github/workflows/testpypi-release.yaml b/.github/workflows/testpypi-release.yaml
index 86c2b900..96b7bd09 100644
--- a/.github/workflows/testpypi-release.yaml
+++ b/.github/workflows/testpypi-release.yaml
@@ -17,7 +17,7 @@ jobs:
     if: ${{ contains( github.event.pull_request.labels.*.name, 'test-build') && github.event_name == 'pull_request' || github.event_name == 'workflow_dispatch' }}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/upstream-dev-ci.yaml b/.github/workflows/upstream-dev-ci.yaml
index 333305ed..1ce9692d 100644
--- a/.github/workflows/upstream-dev-ci.yaml
+++ b/.github/workflows/upstream-dev-ci.yaml
@@ -31,7 +31,7 @@ jobs:
       matrix:
         python-version: ["3.13"]
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0 # Fetch all history for all branches and tags.
       - name: Set environment variables