diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b7b8686..72b9057 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -89,7 +89,7 @@ jobs:
     name: ${{matrix.config.name}}
     runs-on: ${{matrix.config.os}}
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@85e6279cec87321a52edac9c87bce653a07cf6c2 # v4.2.2
 
     # Windows
     - name: Install boost (Windows)