diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9128b16..f8083c0 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,7 +13,7 @@ jobs:
           python-version: "3.9"
 
       - id: cache
-        uses: actions/cache@v1
+        uses: actions/cache@0c45773b623bea8c8e75f6c82b208c3cf94ea4f9 # v4
         with:
           path: ~/.cache/pip
           key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements.txt', '**/test_requirements.txt') }}