diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 0099794..e59dae9 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -45,7 +45,7 @@ jobs:
   pretty:
     runs-on: ubuntu-24.04
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       with:
         submodules: true
     - name: Bootstrap
@@ -80,7 +80,7 @@ jobs:
             gcc_download_url: https://developer.arm.com/-/media/Files/downloads/gnu-rm/9-2019q4/RC2.1/gcc-arm-none-eabi-9-2019-q4-major-x86_64-linux.tar.bz2
             gcc_extract_dir: gcc-arm-none-eabi-9-2019-q4-major
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       with:
         submodules: true
     - name: Bootstrap