diff --git a/.github/workflows/slack.yml b/.github/workflows/slack.yml
index d300b5eebc0..1cbfc4292e4 100644
--- a/.github/workflows/slack.yml
+++ b/.github/workflows/slack.yml
@@ -117,6 +117,7 @@ jobs:
             f.write("payload={}".format(json.dumps(payload)))
 
       - name: Post Slack message
+        if: ${{ steps.prepare.outputs.payload }}
         uses: slackapi/slack-github-action@v2.0.0
         with:
           method: chat.postMessage