diff --git a/.github/workflows/ci.wasm32.yml b/.github/workflows/ci.wasm32.yml
index 33901eb0..8b141f14 100644
--- a/.github/workflows/ci.wasm32.yml
+++ b/.github/workflows/ci.wasm32.yml
@@ -24,7 +24,7 @@ jobs:
           popd
 
       - name: checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: build
         run: |
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a022883b..750f87a8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,7 +12,7 @@ jobs:
         os: [ubuntu-latest, macOS-latest]
         ghc: ['9.2.2', '9.0.2', '8.10.7']
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: haskell/actions/setup@v2
       id: setup-haskell-cabal
       with:
@@ -44,7 +44,7 @@ jobs:
       matrix:
         ghc: ['9.2.2', '9.0.2', '8.10.7']
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - uses: haskell/actions/setup@v2
       id: setup-haskell-cabal
       with:
@@ -76,7 +76,7 @@ jobs:
     # See https://github.com/marketplace/actions/freebsd-vm.
     runs-on: macos-12
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - name: Build
       id: build-freebsd
       uses: vmactions/freebsd-vm@v0