diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0274fe9..f3bda07 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -29,7 +29,7 @@ jobs:
         run: python3 -m unittest discover -s tests -p 'test_*.py'
 
       - name: Cache authentic FCS corpus
-        uses: actions/cache@v4
+        uses: actions/cache@v5
         with:
           path: testdata/.cache/real_world_fcs
           key: real-world-fcs-${{ hashFiles('testdata/real_world_fcs_manifest.json') }}