diff --git a/.github/workflows/site-update.yml b/.github/workflows/site-update.yml
index cd557762..cc52873f 100644
--- a/.github/workflows/site-update.yml
+++ b/.github/workflows/site-update.yml
@@ -19,7 +19,7 @@ jobs:
           path: site
 
       - name: Install SSH key
-        uses: shimataro/ssh-key-action@v2
+        uses: shimataro/ssh-key-action@87a8f067114a8ce263df83e9ed5c849953548bc3 # v2
         with: 
           key: ${{ secrets.SSH_KEY }}
           known_hosts: ${{ secrets.KNOWN_HOSTS }}