diff --git a/.github/workflows/lint-action-workflows.yml b/.github/workflows/lint-action-workflows.yml
index 0bab4d8..e651731 100644
--- a/.github/workflows/lint-action-workflows.yml
+++ b/.github/workflows/lint-action-workflows.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4.1.1
       - name: Check workflow files
         uses: docker://ghcr.io/ponylang/shared-docker-ci-actionlint:20230822
         with:
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 2b7ccc7..50d3053 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -11,7 +11,7 @@ jobs:
     name: Lint entrypoint.py
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: pylint
         run: make pylint
 
@@ -19,7 +19,7 @@ jobs:
     name: Lint bash, docker, markdown, and yaml
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: Lint codebase
         uses: docker://github/super-linter:v3.8.3
         env:
@@ -34,6 +34,6 @@ jobs:
     name: Validate Docker image builds
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: Docker build
         run: make build
diff --git a/.github/workflows/update-release-image.yml b/.github/workflows/update-release-image.yml
index cbd3d4a..85be732 100644
--- a/.github/workflows/update-release-image.yml
+++ b/.github/workflows/update-release-image.yml
@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout source
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4.1.1
       - name: Login to GitHub Container Registry
         # v2.2.0
         uses: docker/login-action@465a07811f14bebb1938fbed4728c6a1ff8901fc
diff --git a/README.md b/README.md
index 4e3967d..8082b32 100644
--- a/README.md
+++ b/README.md
@@ -23,7 +23,7 @@ jobs:
     name: Generate documentation for release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: Generate documentation and upload
         uses: docker://ponylang/library-documentation-action:release
         with:
@@ -53,7 +53,7 @@ jobs:
     name: Generate documentation for release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: Generate documentation and upload
         uses: docker://ponylang/library-documentation-action:release
         with:
@@ -99,7 +99,7 @@ jobs:
     name: Generate documentation for release
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4.1.1
       - name: Generate documentation and upload
         uses: docker://ponylang/library-documentation-action:release
         with: