diff --git a/.github/workflows/reusable-docker-build.yml b/.github/workflows/reusable-docker-build.yml
index 6a45fef2c1..6329808434 100644
--- a/.github/workflows/reusable-docker-build.yml
+++ b/.github/workflows/reusable-docker-build.yml
@@ -54,10 +54,13 @@ env:
   # For a new commit on default branch (main), use the literal tag 'latest' on Docker image.
   # For a new commit on other branches, use the branch name as the tag for Docker image.
   # For a new tag, copy that tag name as the tag for Docker image.
+  # For a pull request, use the name of the base branch that the PR was created against or "latest" (for main).
+  #   e.g. PR against 'main' will use "latest". a PR against 'dspace-7_x' will use 'dspace-7_x'.
   IMAGE_TAGS: |
     type=raw,value=latest,enable=${{ github.ref_name == github.event.repository.default_branch }}
     type=ref,event=branch,enable=${{ github.ref_name != github.event.repository.default_branch }}
     type=ref,event=tag
+    type=raw,value=${{ (github.event.pull_request.base.ref == github.event.repository.default_branch && 'latest') || github.event.pull_request.base.ref }},enable=${{ github.event_name == 'pull_request' }}
   # Define default tag "flavor" for docker/metadata-action per
   # https://github.com/docker/metadata-action#flavor-input
   # We manage the 'latest' tag ourselves to the 'main' branch (see settings above)