diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index bc0420a..284fe9b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,7 +19,7 @@ jobs:
     env:
       RUSTFLAGS: "-D warnings"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - name: Setup Rust toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
@@ -27,7 +27,7 @@ jobs:
           components: rustfmt
 
       - name: Cache rust cargo build files
-        uses: Leafwing-Studios/cargo-cache@v1
+        uses: Leafwing-Studios/cargo-cache@5edda26afa3d28be5d6ee87d4c69c246e3ee37fb # v1
 
       - run: cargo fmt --all -- --check
 
@@ -37,7 +37,7 @@ jobs:
     env:
       RUSTFLAGS: "-D warnings --force-warn deprecated --force-warn dead-code"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - name: Setup Rust toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
@@ -45,7 +45,7 @@ jobs:
           components: clippy
 
       - name: Cache rust cargo build files
-        uses: Leafwing-Studios/cargo-cache@v1
+        uses: Leafwing-Studios/cargo-cache@5edda26afa3d28be5d6ee87d4c69c246e3ee37fb # v1
 
       - run: cargo clippy --all --all-targets --all-features
 
@@ -55,14 +55,14 @@ jobs:
     env:
       RUSTFLAGS: "-D warnings --force-warn deprecated --force-warn dead-code"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - name: Setup Rust toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
 
       - name: Cache rust cargo build files
-        uses: Leafwing-Studios/cargo-cache@v1
+        uses: Leafwing-Studios/cargo-cache@5edda26afa3d28be5d6ee87d4c69c246e3ee37fb # v1
 
       - name: check (release)
         run: cargo check --release --all --all-targets --all-features
@@ -73,14 +73,14 @@ jobs:
     env:
       RUSTFLAGS: "-D warnings --force-warn deprecated --force-warn dead-code"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - name: Setup Rust toolchain
         uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: stable
 
       - name: Cache rust cargo build files
-        uses: Leafwing-Studios/cargo-cache@v1
+        uses: Leafwing-Studios/cargo-cache@5edda26afa3d28be5d6ee87d4c69c246e3ee37fb # v1
 
       - name: Unit tests
         run: cargo test --verbose --workspace --lib -- --nocapture