diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 25de7bc7..424d99f6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -84,7 +84,7 @@ jobs:
       # Baseline is cached via actions/cache; first run creates it (rc=0),
       # subsequent runs compare against it and fail on >20% regression.
       - name: Restore startup baseline (sk.py --version)
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .benchmarks/sk-python-startup-baseline.json
           key: ubuntu-latest-py3.11-sk-python-startup-baseline-v2
diff --git a/.github/workflows/sk-ci.yml b/.github/workflows/sk-ci.yml
index dd1d9c58..8e7d1e0b 100644
--- a/.github/workflows/sk-ci.yml
+++ b/.github/workflows/sk-ci.yml
@@ -50,7 +50,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -69,7 +69,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -78,7 +78,7 @@ jobs:
           key: ubuntu-latest-cargo-startup-${{ hashFiles('sk-rust/Cargo.lock') }}
           restore-keys: ubuntu-latest-cargo-startup-
       - name: Restore startup benchmark baseline
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: .benchmarks/sk-startup-baseline.json
           key: ubuntu-latest-sk-startup-baseline-v2
@@ -104,7 +104,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -132,7 +132,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -166,7 +166,7 @@ jobs:
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: clippy
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
diff --git a/.github/workflows/sk-release.yml b/.github/workflows/sk-release.yml
index ed85ba39..b5656aeb 100644
--- a/.github/workflows/sk-release.yml
+++ b/.github/workflows/sk-release.yml
@@ -25,7 +25,7 @@ jobs:
         with:
           components: clippy
 
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry
@@ -86,7 +86,7 @@ jobs:
         with:
           targets: ${{ matrix.target }}
 
-      - uses: actions/cache@v4
+      - uses: actions/cache@v5
         with:
           path: |
             ~/.cargo/registry