diff --git a/.github/workflows/release-build.yml b/.github/workflows/release-build.yml
index e67f57ceee..dc178857fb 100644
--- a/.github/workflows/release-build.yml
+++ b/.github/workflows/release-build.yml
@@ -48,22 +48,28 @@ jobs:
           echo tag=$(git describe --tags) >> $GITHUB_OUTPUT
           while read branchname
           do
-            #branchname looks like 'develop' or 'r/17.x', the describe + cut looks like '17.x', so we prefix with r/
-            # NB: branchname == develop *should not match* anything so that we fall back to the if case below
+            LAST_BRANCH="$branchname"
+            #branchname looks like 'r/17.x', the describe + cut looks like '17.x', so we prefix with r/
+            # NB: branchname == develop is not handled here, it's handled below
             if [ "$branchname" != "r/`git describe --tags | cut -f 1 -d -`" ]; then
               continue
             fi
             echo "Base branch is $branchname"
             BASE_BRANCH="$branchname"
-            echo "branch=$branchname" >> $GITHUB_OUTPUT
+            echo "branch=$BASE_BRANCH" >> $GITHUB_OUTPUT
             break
           done <<< `gh api \
               -H "Accept: application/vnd.github+json" \
               -H "X-GitHub-Api-Version: 2022-11-28" \
               /repos/${{ github.repository_owner }}/opencast/branches?per_page=100 | \
-            jq -r '. | map(select(.name | match("r/[0-9]*.x|develop"))) | .[].name'`
-          if [ -z "${BASE_BRANCH}" ]; then
-            echo "Base branch is develop"
+            jq -r '. | map(select(.name | match("r/[0-9]*.x"))) | .[].name'`
+          #Figure out what develop branch's version should be
+          # Bash is, without a doubt, the worst possible way to do this, but here we are...
+          export DEVELOP_VERSION=$(($(echo $LAST_BRANCH | cut -f 2 -d '/' | cut -f 1 -d '.') + 1)).x
+          #If we didn't find a match above, *and* the develop branch matches the tag
+          if [ -z "${BASE_BRANCH}" -a "$DEVELOP_VERSION" == "`git describe --tags | cut -f 1 -d -`" ]; then
+            echo "Base branch is develop, version $DEVELOP_VERSION"
+            # Develop is by definition (LAST_BRANCH + 1).x
             echo "branch=develop" >> $GITHUB_OUTPUT
           fi
 
@@ -100,26 +106,26 @@ jobs:
 
       - name: Clone upstream repository
         run: |
-          git clone -b ${{ needs.build.outputs.branch }} "git@github.com:${{ github.repository_owner }}/opencast.git" opencast
+          git clone -b ${{ needs.build-release-tarballs.outputs.branch }} "git@github.com:${{ github.repository_owner }}/opencast.git" opencast
           cd opencast
-          git checkout -b t/admin-ui-${{ needs.build.outputs.tag }}
+          git checkout -b t/admin-ui-${{ needs.build-release-tarballs.outputs.tag }}
 
       - name: Update the admin ui pom file
         working-directory: opencast
         run: |
-          sed -i "s#<interface.sha256>.*</interface.sha256>#<interface.sha256>${{ needs.build.outputs.checksum }}</interface.sha256>#" modules/admin-ui-interface/pom.xml
-          sed -i "s#<interface.url>.*</interface.url>#<interface.url>https://github.com/${{ github.repository_owner }}/opencast-admin-interface/releases/download/${{ needs.build.outputs.tag }}/oc-admin-ui-${{ needs.build.outputs.tag }}.tar.gz</interface.url>#" modules/admin-ui-interface/pom.xml
+          sed -i "s#<interface.sha256>.*</interface.sha256>#<interface.sha256>${{ needs.build-release-tarballs.outputs.checksum }}</interface.sha256>#" modules/admin-ui-interface/pom.xml
+          sed -i "s#<interface.url>.*</interface.url>#<interface.url>https://github.com/${{ github.repository_owner }}/opencast-admin-interface/releases/download/${{ needs.build-release-tarballs.outputs.tag }}/oc-admin-ui-${{ needs.build-release-tarballs.outputs.tag }}.tar.gz</interface.url>#" modules/admin-ui-interface/pom.xml
           git add modules/admin-ui-interface/pom.xml
-          git commit -m "Updating admin ui to ${{ needs.build.outputs.tag }}"
-          git push origin t/admin-ui-${{ needs.build.outputs.tag }}
+          git commit -m "Updating admin ui to ${{ needs.build-release-tarballs.outputs.tag }}"
+          git push origin t/admin-ui-${{ needs.build-release-tarballs.outputs.tag }}
           #This token is an account wide token which allows creation of PRs and pushes.
           echo "${{ secrets.MODULE_PR_TOKEN }}" > token.txt
           gh auth login --with-token < token.txt
           gh pr create \
-            --title "Update ${{ needs.build.outputs.branch }} Admin UI to ${{ needs.build.outputs.tag }}" \
-            --body "Updating Opencast ${{ needs.build.outputs.branch }} Admin UI module to [${{ needs.build.outputs.tag }}](https://github.com/${{ github.repository_owner }}/opencast-admin-interface/releases/tag/${{ needs.build.outputs.tag }})" \
-            --head=${{ github.repository_owner }}:t/admin-ui-${{ needs.build.outputs.tag }} \
-            --base ${{ needs.build.outputs.branch }} \
+            --title "Update ${{ needs.build-release-tarballs.outputs.branch }} Admin UI to ${{ needs.build-release-tarballs.outputs.tag }}" \
+            --body "Updating Opencast ${{ needs.build-release-tarballs.outputs.branch }} Admin UI module to [${{ needs.build-release-tarballs.outputs.tag }}](https://github.com/${{ github.repository_owner }}/opencast-admin-interface/releases/tag/${{ needs.build-release-tarballs.outputs.tag }})" \
+            --head=${{ github.repository_owner }}:t/admin-ui-${{ needs.build-release-tarballs.outputs.tag }} \
+            --base ${{ needs.build-release-tarballs.outputs.branch }} \
             -R ${{ github.repository_owner }}/opencast
             #FIXME: fine grained PATs can't apply labels
             #FIXME: classic PATs don't have the permissions because the PR isn't in an opencastproject (the user) repo