diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 71326eeb6..944c25be1 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -55,7 +55,7 @@ jobs:
     outputs:
       matrix: ${{ steps.versions.outputs.matrix }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
       - id: versions
@@ -142,7 +142,7 @@ jobs:
       matrix:
         py3: ${{ fromJSON(needs.py-versions.outputs.matrix) }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
       - uses: actions/setup-python@v6
@@ -161,7 +161,7 @@ jobs:
       matrix:
         py3: ${{ fromJSON(needs.py-versions.outputs.matrix) }}
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit ('github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -179,7 +179,7 @@ jobs:
     if: ${{ github.actor != 'dependabot[bot]' }} # dependabot cannot access PAT
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}
           ref: ${{ github.ref }}  # dont lock to sha (action needs to push)
@@ -202,7 +202,7 @@ jobs:
 
       # pre-check passed, so proceed...
       - if: ${{ steps.pydep-precheck.outputs.do_generation == 'true' }}
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -228,7 +228,7 @@ jobs:
     needs: [ flake8 ]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -265,7 +265,7 @@ jobs:
       - *free_disk_space
       - *df_disk_space
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -403,7 +403,7 @@ jobs:
       - *free_disk_space
       - *df_disk_space
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -499,7 +499,7 @@ jobs:
       - *free_disk_space
       - *df_disk_space
 
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -598,7 +598,7 @@ jobs:
     needs: [ flake8 ]
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags
@@ -651,7 +651,7 @@ jobs:
           - reco_algo: splinempe_pointed
             dir: "JSON"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
         with:
           ref: ${{ github.sha }}  # lock to triggered commit (github.ref is dynamic)
           fetch-depth: 0  # setuptools-scm needs to access git tags