diff --git a/.github/workflows/book.yml b/.github/workflows/book.yml
index 2c1e2d7..3eb397d 100644
--- a/.github/workflows/book.yml
+++ b/.github/workflows/book.yml
@@ -12,7 +12,7 @@ jobs:
       contents: write
     steps:
       - name: Checkout
-        uses: actions/checkout@v3.5.3
+        uses: actions/checkout@v4.0.0
 
       - name: Setup mdBook
         uses: peaceiris/actions-mdbook@v1.2.0
diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index facf1db..9be8881 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -25,7 +25,7 @@ jobs:
         override: true
         components: rustfmt, clippy
 
-    - uses: actions/checkout@v3.5.3
+    - uses: actions/checkout@v4.0.0
 
     - name: Format
       uses: actions-rs/cargo@v1.0.3
@@ -63,7 +63,7 @@ jobs:
         launchctl unload -w ${SL}/LaunchAgents/${PL}.plist
         sudo launchctl unload -w ${SL}/LaunchDaemons/${PL}.Root.plist
 
-    - uses: actions/checkout@v3.5.3
+    - uses: actions/checkout@v4.0.0
 
     # install stable for kani, cargo-bolero and test runner
     - uses: actions-rs/toolchain@v1.0.7
@@ -97,7 +97,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3.5.3
+    - uses: actions/checkout@v4.0.0
 
     - uses: actions-rs/toolchain@v1.0.7
       id: toolchain
@@ -120,9 +120,9 @@ jobs:
         repo: ["aws/s2n-quic"]
 
     steps:
-    - uses: actions/checkout@v3.5.3
+    - uses: actions/checkout@v4.0.0
 
-    - uses: actions/checkout@v3.5.3
+    - uses: actions/checkout@v4.0.0
       with:
         repository: ${{ matrix.repo }}
         path: "target/integration/${{ matrix.repo }}"