diff --git a/.github/workflows/code.yml b/.github/workflows/code.yml
index cbc3e28..498a35b 100644
--- a/.github/workflows/code.yml
+++ b/.github/workflows/code.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install python packages
         uses: ./.github/actions/install_requirements
@@ -47,7 +47,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Need this to get version number from last tag
           fetch-depth: 0
@@ -77,7 +77,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Need this to get version number from last tag
           fetch-depth: 0
@@ -120,7 +120,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       # image names must be all lower case
       - name: Generate image repo name
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index c510d57..d89a086 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -15,7 +15,7 @@ jobs:
         run: sleep 60
 
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           # Need this to get version number from last tag
           fetch-depth: 0
diff --git a/.github/workflows/docs_clean.yml b/.github/workflows/docs_clean.yml
index a67e188..e324640 100644
--- a/.github/workflows/docs_clean.yml
+++ b/.github/workflows/docs_clean.yml
@@ -18,7 +18,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: gh-pages
 
diff --git a/.github/workflows/linkcheck.yml b/.github/workflows/linkcheck.yml
index 6b64fde..3b24af5 100644
--- a/.github/workflows/linkcheck.yml
+++ b/.github/workflows/linkcheck.yml
@@ -12,7 +12,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install python packages
         uses: ./.github/actions/install_requirements