diff --git a/.github/workflows/backend.yml b/.github/workflows/backend.yml
index 6d1f852..d8ecb6a 100644
--- a/.github/workflows/backend.yml
+++ b/.github/workflows/backend.yml
@@ -42,7 +42,7 @@ jobs:
           key: ${{ env.PHP_EXTENSIONS_CACHE_KEY }}
 
       - name: Cache php extensions
-        uses: actions/cache@v4
+        uses: actions/cache@8b402f58fbc84540c8b491a91e594a4576fec3d7 # v5
         with:
           path: ${{ steps.extcache.outputs.dir }}
           key: ${{ steps.extcache.outputs.key }}
@@ -70,7 +70,7 @@ jobs:
         run: echo "::set-output name=dir::$(composer config cache-files-dir)"
 
       - name: Cache dependencies
-        uses: actions/cache@v4
+        uses: actions/cache@8b402f58fbc84540c8b491a91e594a4576fec3d7 # v5
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: ${{ runner.os }}-${{ hashFiles('**/composer.lock') }}-composer