diff --git a/.github/workflows/build-test-publish.yml b/.github/workflows/build-test-publish.yml
index 5df5b98d..e174e971 100644
--- a/.github/workflows/build-test-publish.yml
+++ b/.github/workflows/build-test-publish.yml
@@ -29,15 +29,15 @@ jobs:
               | jq --exit-status -r '.raw_id_token'
           )
           echo "${REGISTRY_TOKEN}" | docker login '${{ secrets.REGISTRY_HOST }}' -u '${{ secrets.REGISTRY_USER }}' --password-stdin
-      - name: Delete unused internal images
+      - name: Fetch digests of unused internal images
         run: |
           set -x
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:builder'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:build'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:run'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:builder'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:build'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:run'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:builder'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:build'
-          crane delete '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:run'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:builder'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:build'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-18:run'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:builder'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:build'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-20:run'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:builder'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:build'
+          crane digest --full-ref '${{ secrets.REGISTRY_HOST }}/s/${{ secrets.SERVICE_TOKEN_USER_NAME }}/heroku-22:run'