diff --git a/.github/workflows/sync-gitster-git.yml b/.github/workflows/sync-gitster-git.yml
deleted file mode 100644
index 6a3af09..0000000
--- a/.github/workflows/sync-gitster-git.yml
+++ /dev/null
@@ -1,140 +0,0 @@
-name: sync-gitster-git-branches
-
-on:
-  schedule:
-    - cron: '17 6 * * *'
-  workflow_dispatch:
-
-env:
-  SOURCE_REPOSITORY: gitster/git
-  TARGET_REPOSITORY: gitgitgadget/git
-
-# We want to limit queuing to a single workflow run i.e. if there is already
-# an active workflow run and a queued one, queue another one canceling the
-# already queued one.
-concurrency:
-  group: ${{ github.workflow }}
-
-jobs:
-  sync-gitster-git-branches:
-    runs-on: ubuntu-latest
-    steps:
-      - name: check which refs need to be synchronized
-        uses: actions/github-script@v7
-        id: check
-        with:
-          script: |
-            const [targetRepoOwner, targetRepoName] = process.env.TARGET_REPOSITORY.split('/')
-            core.setOutput('target-repo-owner', targetRepoOwner)
-            core.setOutput('target-repo-name', targetRepoName)
-
-            const sleep = async (milliseconds) => {
-              return new Promise(resolve => setTimeout(resolve, milliseconds))
-            }
-
-            const getRefs = async (repository) => {
-              let attemptCounter = 1
-              for (;;) {
-                try {
-                  const [owner, repo] = repository.split('/')
-                  const { data } = await github.rest.git.listMatchingRefs({
-                    owner,
-                    repo,
-                    // We want to match `maint-*` as well as `[a-z][a-z]/*`
-                    // sadly, this is not possible via GitHub's REST API,
-                    // hence we do it below via the `filter()` call.
-                    ref: 'heads/'
-                  })
-                  return data
-                    .filter(e => e.ref.match(/^refs\/heads\/(maint-\d|[a-z][a-z]\/)/))
-                    .sort((a, b) => a.ref.localeCompare(b.ref))
-                } catch (e) {
-                  if (e?.status !== 502) throw e
-                }
-
-                if (++attemptCounter > 10) throw new Error('Giving up listing refs after 10 attempts')
-
-                const seconds = attemptCounter * attemptCounter + 15 * Math.random()
-                core.info(`Encountered a Server Error; retrying in ${seconds} seconds`)
-                await sleep(1000 * seconds)
-              }
-            }
-
-            const sourceRefs = await getRefs(process.env.SOURCE_REPOSITORY)
-            const targetRefs = await getRefs(process.env.TARGET_REPOSITORY)
-
-            const refspecs = []
-            const toFetch = new Set()
-            for (let i = 0, j = 0; i < sourceRefs.length || j < targetRefs.length; ) {
-              const compare =  i >= sourceRefs.length
-                ? +1
-                : j >= targetRefs.length
-                  ? -1
-                  : sourceRefs[i].ref.localeCompare(targetRefs[j].ref)
-              if (compare > 0) {
-                // no source ref => delete target ref
-                refspecs.push(`:${targetRefs[j].ref}`)
-                j++
-              } else if (compare < 0) {
-                // no corresponding target ref yet => push source ref (new)
-                const sha = sourceRefs[i].object.sha
-                toFetch.add(sha)
-                refspecs.push(`${sha}:${sourceRefs[i].ref}`)
-                i++
-              } else {
-                // the sourceRef's name matches the targetRef's
-                if (sourceRefs[i].object.sha !== targetRefs[j].object.sha) {
-                  // target ref needs updating
-                  const sha = sourceRefs[i].object.sha
-                  toFetch.add(sha)
-                  refspecs.push(`+${sha}:${sourceRefs[i].ref}`)
-                }
-                i++
-                j++
-              }
-            }
-
-            core.setOutput('refspec', refspecs.join(' '))
-            targetRefs.forEach((e) => toFetch.delete(e.object.sha))
-            core.setOutput('to-fetch', [...toFetch].join(' '))
-      - name: obtain installation token
-        if: steps.check.outputs.refspec != ''
-        uses: actions/create-github-app-token@v2
-        id: token
-        with:
-          app-id: ${{ secrets.GITGITGADGET_GITHUB_APP_ID }}
-          private-key: ${{ secrets.GITGITGADGET_GITHUB_APP_PRIVATE_KEY }}
-          owner: ${{ steps.check.outputs.target-repo-owner }}
-          repositories: ${{ steps.check.outputs.target-repo-name }}
-      - name: set authorization header
-        if: steps.check.outputs.refspec != ''
-        uses: actions/github-script@v7
-        id: auth
-        with:
-          script: |
-            // Sadly, `git push` does not work with 'Authorization: Bearer <PAT>', therefore
-            // we have to use the `Basic` variant
-            const auth = Buffer.from('PAT:${{ steps.token.outputs.token }}').toString('base64')
-            core.setSecret(auth)
-            core.setOutput('header', `Authorization: Basic ${auth}`)
-      - name: sync
-        if: steps.check.outputs.refspec != ''
-        shell: bash
-        run: |
-          set -ex
-          git init --bare
-
-          git remote add source "${{ github.server_url }}/$SOURCE_REPOSITORY"
-          # pretend to be a partial clone
-          git config remote.source.promisor true
-          git config remote.source.partialCloneFilter blob:none
-
-          # fetch some commits
-          printf '%s' '${{ steps.check.outputs.to-fetch }}' |
-          xargs -d ' ' -r git fetch --depth 10000 source
-          rm -f .git/shallow
-
-          # push the commits
-          printf '%s' '${{ steps.check.outputs.refspec }}' |
-          xargs -d ' ' -r git -c http.extraHeader='${{ steps.auth.outputs.header }}' \
-            push "${{ github.server_url }}/$TARGET_REPOSITORY"
diff --git a/.github/workflows/sync-git-mailing-list-mirror.yml b/.github/workflows/sync-mailing-list-mirror.yml
similarity index 92%
rename from .github/workflows/sync-git-mailing-list-mirror.yml
rename to .github/workflows/sync-mailing-list-mirror.yml
index 89d4bd6..b08b856 100644
--- a/.github/workflows/sync-git-mailing-list-mirror.yml
+++ b/.github/workflows/sync-mailing-list-mirror.yml
@@ -1,9 +1,9 @@
-name: sync-git-mailing-list-mirror
+name: sync-mailing-list-mirror
 
 on:
   workflow_dispatch:
   schedule:
-    - cron:  "2,7,12,17,22,27,32,37,42,47,52,57 * * * *"
+    - cron:  "*/5 * * * *"
 
 env:
   LORE_EPOCH: 1 # also adjust SOURCE_REPOSITORY
@@ -11,11 +11,11 @@ env:
   TARGET_GITHUB_REPOSITORY: gitgitgadget/git-mailing-list-mirror
 
 concurrency:
-  group: sync-git-mailing-list-mirror
+  group: sync-mailing-list-mirror
   cancel-in-progress: true
 
 jobs:
-  sync-git-mailing-list-mirror:
+  sync-mailing-list-mirror:
     runs-on: ubuntu-latest
     permissions:
       contents: write
diff --git a/.github/workflows/sync-git-gui.yml b/.github/workflows/sync-upstream-branches.yml
similarity index 69%
rename from .github/workflows/sync-git-gui.yml
rename to .github/workflows/sync-upstream-branches.yml
index 5f49ac5..f1c39de 100644
--- a/.github/workflows/sync-git-gui.yml
+++ b/.github/workflows/sync-upstream-branches.yml
@@ -1,15 +1,10 @@
-name: sync-git-gui-branches
+name: sync-upstream-branches
 
 on:
   schedule:
     - cron: '31 22 * * *'
   workflow_dispatch:
 
-env:
-  SOURCE_REPOSITORY: j6t/git-gui
-  TARGET_REPOSITORY: gitgitgadget/git
-  TARGET_REF_NAMESPACE: git-gui/
-
 # We want to limit queuing to a single workflow run i.e. if there is already
 # an active workflow run and a queued one, queue another one canceling the
 # already queued one.
@@ -17,15 +12,30 @@ concurrency:
   group: ${{ github.workflow }}
 
 jobs:
-  sync-git-gui-branches:
+  sync-upstream-branches:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        spec:
+          - sourceRepo: j6t/git-gui
+            targetRepo: gitgitgadget/git
+            targetRefNamespace: git-gui/
+          - sourceRepo: gitster/git
+            targetRepo: gitgitgadget/git
+            sourceRefRegex: "^refs/heads/(maint-\\d|[a-z][a-z]/)"
+
     steps:
       - name: check which refs need to be synchronized
         uses: actions/github-script@v7
         id: check
         with:
           script: |
-            const [targetRepoOwner, targetRepoName] = process.env.TARGET_REPOSITORY.split('/')
+            const sourceRepo = ${{ toJSON(matrix.spec.sourceRepo) }}
+            const sourceRefRegexp = ((p) => p ? new RegExp(p) : null)(${{ toJSON(matrix.spec.sourceRefRegex) }})
+            const targetRepo = ${{ toJSON(matrix.spec.targetRepo) }}
+            const targetRefNamespace = ${{ toJSON(matrix.spec.targetRefNamespace) }} || ''
+
+            const [targetRepoOwner, targetRepoName] = targetRepo.split('/')
             core.setOutput('target-repo-owner', targetRepoOwner)
             core.setOutput('target-repo-name', targetRepoName)
 
@@ -38,27 +48,26 @@ jobs:
               for (;;) {
                 try {
                   const [owner, repo] = repository.split('/')
-                  let { data } = await github.rest.git.listMatchingRefs({
-                    owner,
-                    repo,
-                    ref: 'heads/'
-                  })
-
-                  data = data.filter(e => {
-                    if (!e.ref.startsWith('refs/heads/')) return false
-                    e.name = e.ref.slice(11)
-                    return true
-                  })
-
-                  if (stripRefsPrefix) {
-                    data = data.filter(e => {
-                      if (!e.name.startsWith(stripRefsPrefix)) return false
-                      e.name = e.name.slice(stripRefsPrefix.length)
+                  return (
+                    await github.rest.git.listMatchingRefs({
+                      owner,
+                      repo,
+                      // We cannot match `source-ref-regex` as freely as we
+                      // want with GitHub's REST API, hence we do it below via
+                      // the `filter()` call.
+                      ref: 'heads/'
+                    })
+                  ).data
+                    .filter((e) => {
+                      if (sourceRefRegexp && !sourceRefRegexp.test(e.ref)) return false
+                      if (!e.ref.startsWith('refs/heads/')) return false
+                      e.name = e.ref.slice(11)
+                      if (stripRefsPrefix) {
+                        if (!e.name.startsWith(stripRefsPrefix)) return false
+                        e.name = e.name.slice(stripRefsPrefix.length)
+                      }
                       return true
                     })
-                  }
-
-                  return data
                     .sort((a, b) => a.ref.localeCompare(b.ref))
                 } catch (e) {
                   if (e?.status !== 502) throw e
@@ -72,10 +81,10 @@ jobs:
               }
             }
 
-            const sourceRefs = await getRefs(process.env.SOURCE_REPOSITORY)
-            const targetRefs = await getRefs(process.env.TARGET_REPOSITORY, process.env.TARGET_REF_NAMESPACE)
+            const sourceRefs = await getRefs(sourceRepo)
+            const targetRefs = await getRefs(targetRepo, targetRefNamespace)
 
-            const targetPrefix = `refs/heads/${process.env.TARGET_REF_NAMESPACE}`
+            const targetPrefix = `refs/heads/${targetRefNamespace}`
 
             const refspecs = []
             const toFetch = new Set()
@@ -138,7 +147,7 @@ jobs:
           set -ex
           git init --bare
 
-          git remote add source "${{ github.server_url }}/$SOURCE_REPOSITORY"
+          git remote add source '${{ github.server_url }}/${{ matrix.spec.sourceRepo }}'
           # pretend to be a partial clone
           git config remote.source.promisor true
           git config remote.source.partialCloneFilter blob:none
@@ -151,4 +160,4 @@ jobs:
           # push the commits
           printf '%s' '${{ steps.check.outputs.refspec }}' |
           xargs -d ' ' -r git -c http.extraHeader='${{ steps.auth.outputs.header }}' \
-            push "${{ github.server_url }}/$TARGET_REPOSITORY"
+            push '${{ github.server_url }}/${{ matrix.spec.targetRepo }}'
diff --git a/README.md b/README.md
index ac8a925..28d4ef6 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,6 @@ This repository contains GitHub workflows, i.e. automated tasks, that keep [GitG
 
 ## Keeping the mirror of the Git mailing list up to date
 
-The `sync-git-mailing-list.yml` workflow keeps the mirror at https://github.com/gitgitgadget/git-mailing-list of the Git mailing list mirror at https://lore.kernel.org/git up to date. Since that mirror chunks the archive by epochs, this mirror fetches each epoch into its own branch: the oldest epoch into `lore-0`, the next one into `lore-1`, etc.
+The `sync-mailing-list-mirror.yml` workflow keeps the mirror at https://github.com/gitgitgadget/git-mailing-list of the Git mailing list mirror at https://lore.kernel.org/git up to date. Since that mirror chunks the archive by epochs, this mirror fetches each epoch into its own branch: the oldest epoch into `lore-0`, the next one into `lore-1`, etc.
 
 Previously, this workflow lived in the `git-mailing-list` repository in the `sync` branch, which was the default branch because scheduled workflows _must_ live in the default branch.