diff --git a/.github/workflows/run-archiver.yml b/.github/workflows/run-archiver.yml
index 0e111066..1aa41727 100644
--- a/.github/workflows/run-archiver.yml
+++ b/.github/workflows/run-archiver.yml
@@ -76,7 +76,11 @@ jobs:
       - name: Munge summaries together
         id: all_summaries
         run: |
-          ./scripts/make_slack_notification_message.py --summary-files *_run_summary.json | tee -a "$GITHUB_OUTPUT"
+          {
+            echo 'SLACK_PAYLOAD<<EOF'
+            ./scripts/make_slack_notification_message.py --summary-files *_run_summary.json
+            echo EOF
+          } >> "$GITHUB_OUTPUT"
       - name: Inform the Codemonkeys
         uses: slackapi/slack-github-action@v1.24.0
         with:
diff --git a/scripts/make_slack_notification_message.py b/scripts/make_slack_notification_message.py
index 2b359d31..94bbec37 100755
--- a/scripts/make_slack_notification_message.py
+++ b/scripts/make_slack_notification_message.py
@@ -60,7 +60,7 @@ def header_block(text):
 
     print(
         json.dumps(
-            {"attachments": [{"blocks": changed_blocks + unchanged_blocks}]},
+            {"attachments": [{"blocks": changed_blocks + unchanged_blocks}]}, indent=2
         )
     )