diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 018989993..997de6799 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -44,7 +44,7 @@ jobs:
 
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Install dependencies (ubuntu)
         if: ${{ startsWith(matrix.os, 'ubuntu') }}
@@ -135,7 +135,7 @@ jobs:
             binary-release
 
       - name: Upload Artifact
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: mlton.${{ matrix.os }}_${{ matrix.cc }}_${{ matrix.codegen }}
           path: ./*.tgz
diff --git a/.github/workflows/guide.yml b/.github/workflows/guide.yml
index 1e9276164..08280dec5 100644
--- a/.github/workflows/guide.yml
+++ b/.github/workflows/guide.yml
@@ -19,7 +19,7 @@ jobs:
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
         with:
           fetch-depth: 0