diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 02ae1e4..b77eedd 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -382,13 +382,30 @@ jobs:
           name: framed
           path: fastlane/framed
 
+      # Kept, because the check below reads it. `tee` rather than a redirect so
+      # the step still shows what it is doing while it runs.
       - name: write ${{ matrix.app }}'s listing
         env:
           ASC_KEY_ID: ${{ secrets.ASC_KEY_ID }}
           ASC_ISSUER_ID: ${{ secrets.ASC_ISSUER_ID }}
           ASC_KEY_CONTENT: ${{ secrets.ASC_KEY_CONTENT }}
           ODR_VERSION: ${{ steps.version.outputs.version }}
-        run: bundle exec fastlane ios ${{ matrix.lane }}
+        run: |
+          set -o pipefail
+          bundle exec fastlane ios ${{ matrix.lane }} 2>&1 | tee listing.log
+
+      # A picture that did not land is uploaded again, and if the delete of the
+      # failed one does not take, the store keeps both. That leaves a locale
+      # showing the same screenshot twice, which nothing else here would notice
+      # - deliver reports the run as a success. So the retry itself is the
+      # failure: the pictures are up either way, and this says to go and look.
+      - name: the screenshots went up once each
+        run: |
+          set -euo pipefail
+          if grep -q "Failed to upload all screenshots" listing.log; then
+            echo "::error::deliver retried the screenshot upload, which can leave duplicates in App Store Connect. Check ${{ matrix.app }}'s screenshots for every locale before submitting, and re-run this job to upload the set again."
+            exit 1
+          fi
 
   record:
     needs: upload
diff --git a/README.md b/README.md
index 2aa2a9a..feeba2f 100644
--- a/README.md
+++ b/README.md
@@ -133,6 +133,13 @@ It runs as five jobs:
 Both apps always go out together, and nothing chooses one: Pro and Lite are the
 same sources built as two targets, one of which links no ad sdk.
 
+**If a `listing` job fails saying the screenshots did not go up once each**, the
+set is up but a locale may hold a picture twice: deliver uploads what it thinks
+did not land, and a delete that does not take leaves both. Look at the app's
+screenshots in App Store Connect, and fix the set before submitting. Re-running
+the job is worth a try - it clears the set before it uploads - but it has come
+back doubled a second time, so check rather than assume.
+
 **If one app's upload fails, press "Re-run failed jobs".** Only that upload runs
 again, against the `.ipa` already built and signed - build number included, since
 it is baked in at archive time - and `record` runs behind it once it lands.