diff --git a/action.yml b/action.yml
index c8ecfc4..0c69607 100644
--- a/action.yml
+++ b/action.yml
@@ -128,7 +128,7 @@ runs:
   using: "composite"
   steps:
     - name: Restore SSH key cache
-      uses: actions/cache@v4
+      uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
       with:
         path: ${{ runner.temp }}/pullpreview-ssh-keys
         key: pullpreview-ssh-keys-v1-${{ github.repository_id }}-${{ github.run_id }}