diff --git a/.github/workflows/CI_PublishTestPyPI.yml b/.github/workflows/CI_PublishTestPyPI.yml
index 9949f201..4dd8b820 100644
--- a/.github/workflows/CI_PublishTestPyPI.yml
+++ b/.github/workflows/CI_PublishTestPyPI.yml
@@ -30,7 +30,7 @@ jobs:
             openblas_path: "/opt/homebrew/opt/openblas"
             py_tag: "cp310"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: remove python/.gitignore
         shell: bash
         run: |
diff --git a/.github/workflows/PublishPyPI.yml b/.github/workflows/PublishPyPI.yml
index 25cc3e3c..0e0c5a45 100644
--- a/.github/workflows/PublishPyPI.yml
+++ b/.github/workflows/PublishPyPI.yml
@@ -75,7 +75,7 @@ jobs:
             openblas_path: "/opt/homebrew/opt/openblas"
             py_tag: "cp313"
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - name: remove python/.gitignore
         shell: bash
         run: |
diff --git a/.github/workflows/VersionConsistencyCheck.yml b/.github/workflows/VersionConsistencyCheck.yml
index 627ef958..df4db82a 100644
--- a/.github/workflows/VersionConsistencyCheck.yml
+++ b/.github/workflows/VersionConsistencyCheck.yml
@@ -21,7 +21,7 @@ jobs:
     
     steps:
     - name: Checkout code
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       
     - name: Set up Python
       uses: actions/setup-python@v6
diff --git a/.github/workflows/conda.yml b/.github/workflows/conda.yml
index 3cdc7b67..3ca1c403 100644
--- a/.github/workflows/conda.yml
+++ b/.github/workflows/conda.yml
@@ -19,7 +19,7 @@ jobs:
             runner_label: macos-latest
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
     - uses: conda-incubator/setup-miniconda@v3
       with:
         auto-update-conda: true
diff --git a/.github/workflows/test_cxx_backend.yml b/.github/workflows/test_cxx_backend.yml
index 5cd55312..b0737a60 100644
--- a/.github/workflows/test_cxx_backend.yml
+++ b/.github/workflows/test_cxx_backend.yml
@@ -15,7 +15,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
         
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       
       - name: Install dependencies (Ubuntu)
         if: runner.os == 'Linux'
@@ -46,7 +46,7 @@ jobs:
     timeout-minutes: 60  # Allow up to 60 minutes for ILP64 tests
     
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       
       - name: Install dependencies with ILP64 BLAS
         run: |
diff --git a/.github/workflows/test_fortran.yml b/.github/workflows/test_fortran.yml
index dd46f007..c4bed240 100644
--- a/.github/workflows/test_fortran.yml
+++ b/.github/workflows/test_fortran.yml
@@ -13,7 +13,7 @@ jobs:
     name: Fortran with GCC/gfortran
     
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       
       - name: Install dependencies
         run: |
@@ -29,7 +29,7 @@ jobs:
     name: Fortran with Intel compilers
     
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       
       - name: Install Intel oneAPI
         run: |
diff --git a/.github/workflows/test_python.yml b/.github/workflows/test_python.yml
index fb4ce99c..45b3b3c0 100644
--- a/.github/workflows/test_python.yml
+++ b/.github/workflows/test_python.yml
@@ -23,7 +23,7 @@ jobs:
     
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       
       - name: Install system dependencies (Ubuntu)
         if: runner.os == 'Linux'