diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 7772d1c..b06de90 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,6 +8,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+
 jobs:
   test:
     name: ${{ matrix.rust }} / ${{ matrix.os }}
@@ -35,6 +38,8 @@ jobs:
             os: ubuntu-latest
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@3c5f7ea28cd621ae0bf5283f0e981fb97b8a7af9 # master
@@ -90,6 +95,8 @@ jobs:
       WASM_BINDGEN_SHA256: "3039f38f65fe237b640cf06a140c919ca8d717ec5012146d145d3f27bb4d6b28" # pragma: allowlist secret
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable
@@ -141,6 +148,8 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # stable