diff --git a/.github/workflows/benchmark.yml b/.github/workflows/benchmark.yml
index a65602f07..311387c3e 100644
--- a/.github/workflows/benchmark.yml
+++ b/.github/workflows/benchmark.yml
@@ -20,7 +20,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python ${{ matrix.python-version }}
         uses: astral-sh/setup-uv@v7
@@ -77,7 +77,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: astral-sh/setup-uv@v7
diff --git a/.github/workflows/codegen.yml b/.github/workflows/codegen.yml
index 5a8f240f3..144183584 100644
--- a/.github/workflows/codegen.yml
+++ b/.github/workflows/codegen.yml
@@ -21,7 +21,7 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python ${{ matrix.python-version }}
         uses: astral-sh/setup-uv@v7
diff --git a/.github/workflows/commit.yml b/.github/workflows/commit.yml
index 69b32d505..c30b00225 100644
--- a/.github/workflows/commit.yml
+++ b/.github/workflows/commit.yml
@@ -18,7 +18,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: astral-sh/setup-uv@v7
@@ -41,7 +41,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: astral-sh/setup-uv@v7
@@ -75,7 +75,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: astral-sh/setup-uv@v7
@@ -123,12 +123,12 @@ jobs:
     timeout-minutes: 60
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           path: flopy
 
       - name: Checkout MODFLOW 6
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: MODFLOW-ORG/modflow6
           path: modflow6
diff --git a/.github/workflows/examples.yml b/.github/workflows/examples.yml
index 917924ff3..a2b53f380 100644
--- a/.github/workflows/examples.yml
+++ b/.github/workflows/examples.yml
@@ -19,7 +19,7 @@ jobs:
     timeout-minutes: 90
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Micromamba
         uses: mamba-org/setup-micromamba@v2
diff --git a/.github/workflows/mf6.yml b/.github/workflows/mf6.yml
index 4909bb15d..db3e9dbe0 100644
--- a/.github/workflows/mf6.yml
+++ b/.github/workflows/mf6.yml
@@ -22,12 +22,12 @@ jobs:
     steps:
 
     - name: Checkout flopy repo
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         path: flopy
 
     - name: Checkout MODFLOW 6
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: MODFLOW-ORG/modflow6
         path: modflow6
@@ -99,18 +99,18 @@ jobs:
     steps:
 
     - name: Checkout flopy repo
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         path: flopy
 
     - name: Checkout MODFLOW 6
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: MODFLOW-ORG/modflow6
         path: modflow6
 
     - name: Checkout MF6 examples
-      uses: actions/checkout@v5
+      uses: actions/checkout@v6
       with:
         repository: MODFLOW-ORG/modflow6-examples
         path: modflow6-examples
diff --git a/.github/workflows/optional.yml b/.github/workflows/optional.yml
index 947f24a22..c62a87f8c 100644
--- a/.github/workflows/optional.yml
+++ b/.github/workflows/optional.yml
@@ -25,7 +25,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Setup Python
         uses: astral-sh/setup-uv@v7
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 82c4aa16b..8e7c9b84f 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -20,7 +20,7 @@ jobs:
     steps:
 
       - name: Checkout release branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
@@ -140,7 +140,7 @@ jobs:
     steps:
 
       - name: Checkout release branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ github.ref_name }}
 
@@ -169,7 +169,7 @@ jobs:
     steps:
 
       - name: Checkout master branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: master
 
@@ -206,7 +206,7 @@ jobs:
     steps:
 
       - name: Checkout master branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: master
 
diff --git a/.github/workflows/rtd.yml b/.github/workflows/rtd.yml
index cda6eede8..8fee6ece7 100644
--- a/.github/workflows/rtd.yml
+++ b/.github/workflows/rtd.yml
@@ -39,7 +39,7 @@ jobs:
           echo "ref=$ref" >> $GITHUB_OUTPUT
 
       - name: Checkout flopy repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ steps.set_ref.outputs.ref }}
 
@@ -68,13 +68,13 @@ jobs:
 
     steps:
       - name: Checkout flopy repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           ref: ${{ needs.set_options.outputs.ref }}
           path: flopy
 
       - name: Checkout MODFLOW 6
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
         with:
           repository: MODFLOW-ORG/modflow6
           path: modflow6