diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index aca6882f2a6..a223af655ad 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -177,7 +177,7 @@ jobs:
           mvn -q checkstyle:checkstyle license:check
       # spoon dataflow
       - name: Cache downloaded file
-        uses: actions/cache@v2
+        uses: actions/cache@8492260343ad570701412c2f464a5877dc76bace # v2
         with:
           path: spoon-dataflow/z3-4.8.4.d6df51951f4c-x64-ubuntu-14.04.zip
           key: ${{ runner.os }}-z3-4.8.4.d6df51951f4c-x64-ubuntu-14.04.zip