diff --git a/.github/workflows/code.yml b/.github/workflows/code.yml
index 7f8b21e..1d2e39c 100644
--- a/.github/workflows/code.yml
+++ b/.github/workflows/code.yml
@@ -22,7 +22,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install python packages
         uses: ./.github/actions/install_requirements
@@ -49,7 +49,7 @@ 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
@@ -87,7 +87,7 @@ 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
@@ -127,7 +127,7 @@ 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 3454992..ff144a5 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -19,7 +19,7 @@ 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 472669c..85834f3 100644
--- a/.github/workflows/docs_clean.yml
+++ b/.github/workflows/docs_clean.yml
@@ -22,7 +22,7 @@ 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 3dd250b..208862e 100644
--- a/.github/workflows/linkcheck.yml
+++ b/.github/workflows/linkcheck.yml
@@ -16,7 +16,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install python packages
         uses: ./.github/actions/install_requirements