diff --git a/.github/workflows/cleanup_images.yml b/.github/workflows/cleanup_images.yml
index 8b5ae564..b7205b42 100644
--- a/.github/workflows/cleanup_images.yml
+++ b/.github/workflows/cleanup_images.yml
@@ -31,12 +31,15 @@ jobs:
   cleanup:
     runs-on: ubuntu-latest
     steps:
+      - name: Convert PACKAGE_NAMES to comma-separated list
+        run: echo "PACKAGES=$(echo ${{ env.PACKAGE_NAMES }} | tr '\n' ',' | sed 's/,$//')" >> $GITHUB_ENV
+
       - name: Remove tag ${{format('pr-{0}', github.event.pull_request.number)}}
         uses: dataaxiom/ghcr-cleanup-action@98b4022383d6ddb70ccbf6a378b4d8c67a60f066
         with:
           token: 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
           owner: Alfresco
           repository: alfresco-dockerfiles-bakery
-          packages: ${{ env.PACKAGE_NAMES }}
+          packages: ${{ env.PACKAGES }}
           delete-tags: ${{format('pr-{0}', github.event.pull_request.number)}}
           dry-run: true