diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index e89d1db3..c9259a62 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -54,7 +54,7 @@ jobs:
 
     - name: Send email on failure
       if: failure()
-      uses: firebase/firebase-admin-node/.github/actions/send-email
+      uses: firebase/firebase-admin-node/.github/actions/send-email@master
       with:
         api-key: ${{ secrets.OSS_BOT_MAILGUN_KEY }}
         domain: ${{ secrets.OSS_BOT_MAILGUN_DOMAIN }}
@@ -69,7 +69,7 @@ jobs:
 
     - name: Send email on cancelled
       if: cancelled()
-      uses: firebase/firebase-admin-node/.github/actions/send-email
+      uses: firebase/firebase-admin-node/.github/actions/send-email@master
       with:
         api-key: ${{ secrets.OSS_BOT_MAILGUN_KEY }}
         domain: ${{ secrets.OSS_BOT_MAILGUN_DOMAIN }}