diff --git a/.github/workflows/check-imports.yml b/.github/workflows/check-imports.yml
index eda4feff8..f87a15405 100644
--- a/.github/workflows/check-imports.yml
+++ b/.github/workflows/check-imports.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       - name: Update ArkLib.lean
         run: ./scripts/update-lib.sh
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c0c4905fe..5b7d2f7b1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       # uses lean standard action with all default input values
       - uses: leanprover/lean-action@v1.3.0
         with:
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 0e4fee5f9..b59d1f1c3 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout project
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
 
       # --- Lean and Blueprint Build ---
       - name: Cache Lean dependencies