diff --git a/.github/actions/cargo-cache/action.yml b/.github/actions/cargo-cache/action.yml
index ceffcc3..20a8f74 100644
--- a/.github/actions/cargo-cache/action.yml
+++ b/.github/actions/cargo-cache/action.yml
@@ -3,14 +3,14 @@ runs:
   using: composite
   steps:
     - name: Cache registry
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ~/.cargo/registry/
         key: cargo-registry-${{ runner.os }}-${{ hashFiles('Cargo.lock') }}
         restore-keys: |
           cargo-registry-${{ runner.os }}
     - name: Cache build
-      uses: actions/cache@v3
+      uses: actions/cache@v4
       with:
         path: ./target/
         key: target-${{ runner.os }}-${{ github.sha }}
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index f7c4c48..b6292f8 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -12,17 +12,17 @@ jobs:
     name: Validate Nix
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v25
       - run: nix flake check
 
   check:
     name: Check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: rm -rf ~/.cargo/
-      - uses: cachix/install-nix-action@v22
+      - uses: cachix/install-nix-action@v25
       - uses: ./.github/actions/cargo-cache
       - run: nix develop -c cargo check
 
@@ -30,9 +30,9 @@ jobs:
     name: Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: rm -rf ~/.cargo/
-      - uses: cachix/install-nix-action@v22
+      - uses: cachix/install-nix-action@v25
       - uses: ./.github/actions/cargo-cache
       - run: nix develop -c cargo test
 
@@ -40,9 +40,9 @@ jobs:
     name: Lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: rm -rf ~/.cargo/
-      - uses: cachix/install-nix-action@v22
+      - uses: cachix/install-nix-action@v25
       - uses: ./.github/actions/cargo-cache
       # See: https://github.com/rust-lang/rust-clippy/issues/1209
       - run: RUSTFLAGS="-D warnings" nix develop -c cargo clippy --all-targets
@@ -51,7 +51,7 @@ jobs:
     name: Check formatting
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: rm -rf ~/.cargo/
-      - uses: cachix/install-nix-action@v22
+      - uses: cachix/install-nix-action@v25
       - run: nix develop -c cargo fmt --check
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
index 90758b9..d0bed98 100644
--- a/.github/workflows/deploy.yml
+++ b/.github/workflows/deploy.yml
@@ -18,8 +18,8 @@ jobs:
     env:
       AWS_DEFAULT_REGION: us-west-2
     steps:
-      - uses: actions/checkout@v3
-      - uses: cachix/install-nix-action@v22
+      - uses: actions/checkout@v4
+      - uses: cachix/install-nix-action@v25
 
       - name: Build
         # Docker is preinstalled.
@@ -69,19 +69,20 @@ jobs:
     if: github.event.workflow_run.conclusion == 'success'
     runs-on: ubuntu-latest
     permissions:
+      actions: read
       contents: read
       id-token: write
       pages: write
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: rm -rf ~/.cargo/
-      - uses: cachix/install-nix-action@v22
+      - uses: cachix/install-nix-action@v25
       - uses: ./.github/actions/cargo-cache
       - run: |
           nix develop -c cargo doc --no-deps
           rm ./target/doc/.lock
           echo '<meta http-equiv="refresh" content="0; url=mercury">' > ./target/doc/index.html
-      - uses: actions/upload-pages-artifact@v1
+      - uses: actions/upload-pages-artifact@v3
         with:
           path: ./target/doc/
-      - uses: actions/deploy-pages@v2
+      - uses: actions/deploy-pages@v4