diff --git a/.github/workflows/deploy-docs.yml b/.github/workflows/deploy-docs.yml
index add03db..79f270c 100644
--- a/.github/workflows/deploy-docs.yml
+++ b/.github/workflows/deploy-docs.yml
@@ -28,7 +28,7 @@ jobs:
           python-version: 3.x
 
       - run: echo "cache_id=$(date --utc '+%V')" >> $GITHUB_ENV
-      - uses: actions/cache@v4
+      - uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
         with:
           key: mkdocs-material-${{ env.cache_id }}
           path: .cache