diff --git a/.github/workflows/build-admb-and-ss3-from-source.yml b/.github/workflows/build-admb-and-ss3-from-source.yml
index 93fa1a99..ffa7feaa 100644
--- a/.github/workflows/build-admb-and-ss3-from-source.yml
+++ b/.github/workflows/build-admb-and-ss3-from-source.yml
@@ -26,7 +26,7 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
     # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
 
       - name: Update Homebrew
         if: matrix.config.os == 'macos-15-intel'
@@ -47,7 +47,7 @@ jobs:
 
     # Checkout ADMB repository
       - name: Checkout admb
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: admb-project/admb
           path: admb
diff --git a/.github/workflows/build-ss3-warnings.yml b/.github/workflows/build-ss3-warnings.yml
index 463f66a1..49257008 100644
--- a/.github/workflows/build-ss3-warnings.yml
+++ b/.github/workflows/build-ss3-warnings.yml
@@ -33,7 +33,7 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Update Ubuntu packages
         run: sudo apt-get update
diff --git a/.github/workflows/build-ss3.yml b/.github/workflows/build-ss3.yml
index aa4f86d2..76720771 100644
--- a/.github/workflows/build-ss3.yml
+++ b/.github/workflows/build-ss3.yml
@@ -38,13 +38,13 @@ jobs:
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - name: checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-source-code'
           
       # Checkout ADMB repository
       - name: Checkout admb for macos-15-intel build
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: admb-project/admb
           path: admb
diff --git a/.github/workflows/run-ss3-bootstrap.yml b/.github/workflows/run-ss3-bootstrap.yml
index 66348f89..372e54e2 100644
--- a/.github/workflows/run-ss3-bootstrap.yml
+++ b/.github/workflows/run-ss3-bootstrap.yml
@@ -32,10 +32,10 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Checkout test models repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-test-models'
           path: test-models-repo
diff --git a/.github/workflows/run-ss3-mcmc.yml b/.github/workflows/run-ss3-mcmc.yml
index a95fc7d3..8c7aca77 100644
--- a/.github/workflows/run-ss3-mcmc.yml
+++ b/.github/workflows/run-ss3-mcmc.yml
@@ -31,10 +31,10 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Checkout models repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-test-models'
           path: test-models-repo
diff --git a/.github/workflows/run-ss3-no-est.yml b/.github/workflows/run-ss3-no-est.yml
index 1e66ea6b..e5d23815 100644
--- a/.github/workflows/run-ss3-no-est.yml
+++ b/.github/workflows/run-ss3-no-est.yml
@@ -28,7 +28,7 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
  #     - name: Get last compiled version of SS; alternative to compiling in same wkflow
  #       uses: dawidd6/action-download-artifact@v2
@@ -39,7 +39,7 @@ jobs:
  #         path: ss_linux
 
       - name: Checkout models repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-test-models'
           path: test-models-repo
diff --git a/.github/workflows/run-ss3-with-est.yml b/.github/workflows/run-ss3-with-est.yml
index c3224e1d..1accd96a 100644
--- a/.github/workflows/run-ss3-with-est.yml
+++ b/.github/workflows/run-ss3-with-est.yml
@@ -32,10 +32,10 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Checkout models repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-test-models'
           path: test-models-repo
diff --git a/.github/workflows/test-r4ss-with-ss3.yml b/.github/workflows/test-r4ss-with-ss3.yml
index 00a7d505..a81119ba 100644
--- a/.github/workflows/test-r4ss-with-ss3.yml
+++ b/.github/workflows/test-r4ss-with-ss3.yml
@@ -32,10 +32,10 @@ jobs:
 
     steps:
       - name: Checkout ss3 repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Checkout models repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: 'nmfs-ost/ss3-test-models'
           path: test-models-repo
diff --git a/.github/workflows/test-simple-with-ss3-artifacts.yml b/.github/workflows/test-simple-with-ss3-artifacts.yml
index e9110653..b4393e82 100644
--- a/.github/workflows/test-simple-with-ss3-artifacts.yml
+++ b/.github/workflows/test-simple-with-ss3-artifacts.yml
@@ -45,7 +45,7 @@ jobs:
 
     steps:
       - name: Checkout SS3 Test Models
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: nmfs-ost/ss3-test-models
           path: ss3-test-models