diff --git a/bin/repair-renamed-labels b/bin/repair-renamed-labels
new file mode 100755
index 00000000..7eabf4c1
--- /dev/null
+++ b/bin/repair-renamed-labels
@@ -0,0 +1,112 @@
+#!/usr/bin/env node
+/**
+ * Labels renamed on GitHub before Pulldasher handled the `label` webhook
+ * left their old names on the PRs and issues it stores. This finds every
+ * stored label its repo no longer has, reads each carrying PR's or issue's
+ * labels off GitHub for the name it has now, and with --apply renames the
+ * stored rows in place (a refresh would drop who added the label and when,
+ * which the Projects tab sorts by), moving a renamed project's slug-kept
+ * state too (lib/work.js renameProject). Run it with the instance's config:
+ *
+ *   docker exec pulldasher bin/repair-renamed-labels [--apply]
+ *
+ * Without --apply it only lists. A label with no single new name (deleted,
+ * or its items now disagree) is listed and left alone.
+ */
+import config from '../lib/config-loader.js';
+import db from '../lib/db.js';
+import dbManager from '../lib/db-manager.js';
+import git from '../lib/git-manager.js';
+import { projectSettings } from '../lib/projects.js';
+import { loadSettings } from '../lib/settings.js';
+import { renameProject } from '../lib/work.js';
+
+const apply = process.argv.includes('--apply');
+// items read off GitHub per stale label
+const SAMPLE = 5;
+const split = repo => ({ owner: repo.split('/')[0], repo: repo.split('/')[1] });
+
+async function repoLabels(repo) {
+   const names = new Set();
+   for (let page = 1; ; page++) {
+      const { data } = await git.github.issues.listLabelsForRepo({
+         ...split(repo),
+         per_page: 100,
+         page,
+      });
+      for (const l of data) names.add(l.name.toLowerCase());
+      if (data.length < 100) return names;
+   }
+}
+
+try {
+   await loadSettings();
+   const settings = config.projects ? projectSettings() : null;
+   const stored = await db.query('SELECT DISTINCT `repo`, `title` FROM `pull_labels`');
+   const byRepo = new Map();
+   for (const row of stored) byRepo.set(row.repo, [...(byRepo.get(row.repo) ?? []), row.title]);
+
+   const renames = [];
+   for (const [repo, titles] of byRepo) {
+      let live;
+      try {
+         live = await repoLabels(repo);
+      } catch (err) {
+         console.log('%s: skipped, its labels can’t be read (%s)', repo, err.status ?? err.message);
+         continue;
+      }
+      for (const title of titles.filter(t => !live.has(t.toLowerCase()))) {
+         const nums = (
+            await db.query(
+               'SELECT `number` FROM `pull_labels` WHERE `repo` = ? AND `title` = ? ORDER BY `number` DESC',
+               [repo, title]
+            )
+         ).map(r => r.number);
+         // the new name: on GitHub on every item checked, and stored on none
+         // of them; a few items say it, and an old label on thousands of
+         // merged PRs would spend the board's GitHub quota
+         let now = null;
+         for (const number of nums.slice(0, SAMPLE)) {
+            const data = await git.github.issues
+               .listLabelsOnIssue({ ...split(repo), number })
+               .then(res => res.data)
+               // deleted or moved away: it says nothing about the new name
+               .catch(err => (err.status === 404 ? null : Promise.reject(err)));
+            if (!data) continue;
+            const mine = (await dbManager.getLabels(repo, number)).map(l => l.data.title);
+            const fresh = data.map(l => l.name).filter(name => !mine.includes(name));
+            now = now ? now.filter(name => fresh.includes(name)) : fresh;
+         }
+         const to = now?.length === 1 ? now[0] : null;
+         console.log(
+            '%s: "%s" on %s -> %s',
+            repo,
+            title,
+            nums
+               .slice(0, SAMPLE)
+               .map(n => '#' + n)
+               .join(' ') + (nums.length > SAMPLE ? ` and ${nums.length - SAMPLE} more` : ''),
+            to ? `"${to}"` : `no single new name (${now?.join(', ') || 'none'}), left alone`
+         );
+         if (to) renames.push({ repo, from: title, to });
+      }
+   }
+
+   if (apply) {
+      for (const { repo, from, to } of renames) await dbManager.renameLabel(repo, from, to);
+      const slug = name =>
+         settings && name.startsWith(settings.prefix) ? name.slice(settings.prefix.length) : null;
+      const moves = new Map(
+         renames.filter(r => slug(r.from) && slug(r.to)).map(r => [slug(r.from), slug(r.to)])
+      );
+      for (const [from, to] of moves) {
+         const moved = await renameProject(settings, from, to);
+         console.log('project %s -> %s: %s', from, to, moved ? 'moved' : 'old label still in use');
+      }
+      console.log('Renamed %d stored labels.', renames.length);
+   } else if (renames.length) {
+      console.log('Dry run: --apply renames the %d above.', renames.length);
+   }
+} finally {
+   db.end();
+}
diff --git a/controllers/githubHooks.js b/controllers/githubHooks.js
index 4e6f19de..61d83ec1 100644
--- a/controllers/githubHooks.js
+++ b/controllers/githubHooks.js
@@ -25,7 +25,13 @@ function withTimeout(promise, ms) {
    return Promise.race([promise, late]).finally(() => clearTimeout(timer));
 }
 import { projectSettings } from '../lib/projects.js';
-import { forgetIssue, workIssueTouched, workPullTouched } from '../lib/work.js';
+import {
+   forgetIssue,
+   renameProject,
+   syncWork,
+   workIssueTouched,
+   workPullTouched,
+} from '../lib/work.js';
 
 const hooksDebug = debug('pulldasher:hooks');
 
@@ -255,6 +261,8 @@ const HooksController = {
             completed_at: body.check_run.completed_at,
          });
          dbUpdated = dbManager.updateCommitStatus(status);
+      } else if (event === 'label') {
+         dbUpdated = Promise.resolve(handleLabelRename(body));
       }
 
       if (dbUpdated) {
@@ -313,6 +321,36 @@ function handleIssueEvent(body) {
    });
 }
 
+/**
+ * A repo's label renamed on GitHub (the `label` event, `edited` with
+ * `changes.name`). GitHub sends no labeled/unlabeled for the PRs and issues
+ * carrying it, so their stored labels take the new name here; a project
+ * label's rename moves the project too (renameProject).
+ */
+async function handleLabelRename(body) {
+   const from = body.changes?.name?.from;
+   if (body.action !== 'edited' || !from) return;
+   const repo = body.repository.full_name;
+   const to = body.label.name;
+   hooksDebug('Renamed label: %s -> %s in %s', from, to, repo);
+   const open = await dbManager.renameLabel(repo, from, to);
+   for (const number of open) queue.markPullAsDirty(repo, number);
+
+   const settings = projectSettings();
+   if (!settings) return;
+   const slugOf = name =>
+      name.startsWith(settings.prefix) ? name.slice(settings.prefix.length) : null;
+   const [was, now] = [slugOf(from), slugOf(to)];
+   if (was == null && now == null) return;
+   if (was != null && now != null) await renameProject(settings, was, now);
+   // the Projects tab reads labels and slugs: open boards fetch again once
+   // the work is read (app.js listens for the sync); not awaited, like a
+   // labeled issue's sync
+   syncWork(settings).catch(err =>
+      console.error('Work sync after a label rename failed: %s', (err && err.message) || err)
+   );
+}
+
 /**
  * Handles the response body if it represents a labeled / unlabled issue
  * (or pull) event and returns a promise that is fulfilled when the DB change
diff --git a/lib/db-manager.js b/lib/db-manager.js
index fa10d41d..6543f270 100644
--- a/lib/db-manager.js
+++ b/lib/db-manager.js
@@ -522,6 +522,37 @@ const dbManager = {
       return DBComment.delete(repo, 'review', comment_id);
    },
 
+   /**
+    * A label renamed on GitHub: every PR and issue in `repo` carrying `from`
+    * carries `to` now. Resolves to the numbers of the open PRs among them,
+    * the ones the board shows.
+    */
+   renameLabel: async function renameLabel(repo, from, to) {
+      dbDebug("Calling renameLabel for '%s' -> '%s' in repo %s", from, to, repo);
+      const open = await db.query(
+         'SELECT l.number FROM pull_labels l JOIN pulls p ON p.repo = l.repo AND ' +
+            "p.number = l.number WHERE l.repo = ? AND l.title = ? AND p.state = 'open'",
+         [repo, from]
+      );
+      // a row already under the new name (left by a missed webhook) stays,
+      // and the old one beside it goes. Titles compare without case, so on a
+      // case-only rename the join would match each row to itself. (Not
+      // UPDATE IGNORE: it would cut a name longer than the column to fit.)
+      if (from.toLowerCase() !== to.toLowerCase()) {
+         await db.query(
+            'DELETE o FROM pull_labels o JOIN pull_labels n ON n.repo = o.repo AND ' +
+               'n.number = o.number AND n.title = ? WHERE o.repo = ? AND o.title = ?',
+            [to, repo, from]
+         );
+      }
+      await db.query('UPDATE pull_labels SET title = ? WHERE repo = ? AND title = ?', [
+         to,
+         repo,
+         from,
+      ]);
+      return open.map(row => row.number);
+   },
+
    /**
     * Returns a promise which resolves when all the labels for pull `number`
     *  have been deleted from the database.
diff --git a/lib/work.js b/lib/work.js
index 4a4a8840..50ae88c2 100644
--- a/lib/work.js
+++ b/lib/work.js
@@ -4,6 +4,7 @@ import git from './git-manager.js';
 import { issueRepos, loadProjects } from './projects.js';
 import { isBot } from './review-model.js';
 import { listItems } from './roadmap.js';
+import { saveSetting, savedSetting } from './settings.js';
 import {
    MISC_SLUG,
    SUGGEST_DAYS,
@@ -419,6 +420,45 @@ export async function forgetIssue(ref, now = Math.floor(Date.now() / 1000)) {
    await db.query('DELETE FROM `issues` WHERE `repo` = ? AND `number` = ?', [ref.repo, ref.number]);
 }
 
+/**
+ * A project label was renamed on GitHub (its PRs and issues already carry
+ * the new name). What's kept by slug moves with it: the issues added by hand
+ * or by a link, the roadmap item, and the ongoing mark. A project's label
+ * lives in many repos and each one's rename arrives on its own, so this
+ * waits until no repo has a PR or issue under the old label: the last
+ * repo's rename moves the project. Resolves whether it moved.
+ */
+export async function renameProject(settings, from, to) {
+   const old = settings.prefix + from;
+   // titles compare without case: BINARY keeps a case-only rename from
+   // counting the renamed rows as the old label
+   const [left] = await db.query(
+      'SELECT COUNT(*) AS `n` FROM `pull_labels` WHERE `title` = ? AND BINARY `title` = ?',
+      [old, old]
+   );
+   if (Number(left.n)) return false;
+   // an issue the new project has already keeps its own row
+   await db.query('UPDATE IGNORE `project_issues` SET `project` = ? WHERE `project` = ?', [
+      to,
+      from,
+   ]);
+   // a project has one roadmap item: one tracking the new slug already stays
+   // the project's, and the old one is left for a person to merge
+   const [taken] = await db.query(
+      'SELECT COUNT(*) AS `n` FROM `roadmap_items` WHERE `project` = ? AND `project` <> ? AND `removed_at` IS NULL',
+      [to, from]
+   );
+   if (!Number(taken.n)) {
+      await db.query('UPDATE `roadmap_items` SET `project` = ? WHERE `project` = ?', [to, from]);
+   }
+   const ongoing = savedSetting('ongoing_projects');
+   if (ongoing?.includes(from)) {
+      const moved = [...new Set(ongoing.map(slug => (slug === from ? to : slug)))].sort();
+      await saveSetting('ongoing_projects', moved, null);
+   }
+   return true;
+}
+
 /** Read the issues added by hand or by a link off GitHub again, and keep
  * their titles and states current. Resolves their refs. */
 async function refreshHandIssues() {
diff --git a/test/hooks-label-rename.test.js b/test/hooks-label-rename.test.js
new file mode 100644
index 00000000..62bf2ee0
--- /dev/null
+++ b/test/hooks-label-rename.test.js
@@ -0,0 +1,120 @@
+import { test, afterEach, mock } from 'node:test';
+import assert from 'node:assert/strict';
+import HooksController from '../controllers/githubHooks.js';
+import config from '../lib/config-loader.js';
+import db from '../lib/db.js';
+import queue from '../lib/pull-queue.js';
+import { _resetSettings, loadSettings } from '../lib/settings.js';
+import { renameProject } from '../lib/work.js';
+
+afterEach(() => {
+   mock.restoreAll();
+   _resetSettings();
+});
+
+// every query, and what each kind answers
+function fakeDb(answers = {}) {
+   const queries = [];
+   mock.method(db, 'query', async (sql, params) => {
+      queries.push({ sql, params });
+      for (const [pattern, rows] of Object.entries(answers)) {
+         if (sql.includes(pattern)) return typeof rows === 'function' ? rows(params) : rows;
+      }
+      return sql.includes('COUNT(*)') ? [{ n: 0 }] : [];
+   });
+   return queries;
+}
+
+function send(event, body) {
+   const req = {
+      query: { secret: 'test-hook-secret' },
+      headers: { 'content-type': 'application/json' },
+      body,
+      get: () => event,
+   };
+   return new Promise(resolve => {
+      const res = { status: () => res, send: resolve };
+      HooksController.main(req, res);
+   });
+}
+
+const renamed = (from, to) => ({
+   action: 'edited',
+   label: { name: to },
+   changes: { name: { from } },
+   repository: { full_name: 'o/r' },
+});
+
+test('a renamed label moves to the new name on every row in the repo', async () => {
+   const saved = config.projects;
+   config.projects = undefined;
+   const queries = fakeDb({ 'JOIN pulls': [{ number: 7 }] });
+   const dirty = [];
+   mock.method(queue, 'markPullAsDirty', (repo, number) => dirty.push(`${repo}#${number}`));
+
+   await send('label', renamed('P-strapi-shared-fields', 'P-strapi-cli'));
+   config.projects = saved;
+
+   // a row already under the new name goes first, so the update can't collide
+   const writes = queries.filter(q => /^(DELETE|UPDATE)/.test(q.sql));
+   assert.deepEqual(
+      writes.map(q => [q.sql.split(' ')[0], q.params]),
+      [
+         ['DELETE', ['P-strapi-cli', 'o/r', 'P-strapi-shared-fields']],
+         ['UPDATE', ['P-strapi-cli', 'o/r', 'P-strapi-shared-fields']],
+      ]
+   );
+   // the open PR the board shows is sent again
+   assert.deepEqual(dirty, ['o/r#7']);
+});
+
+test('a case-only rename keeps the renamed rows', async () => {
+   const saved = config.projects;
+   config.projects = undefined;
+   const queries = fakeDb();
+   await send('label', renamed('P-Docs', 'P-docs'));
+   config.projects = saved;
+   assert.ok(queries.some(q => q.sql.startsWith('UPDATE pull_labels')));
+   assert.ok(!queries.some(q => q.sql.startsWith('DELETE')));
+});
+
+test('a label edit with no new name, a new label, or a deleted one changes nothing', async () => {
+   const queries = fakeDb();
+   await send('label', { ...renamed('a', 'a'), changes: { color: { from: 'fff' } } });
+   await send('label', { ...renamed('a', 'a'), action: 'created', changes: undefined });
+   await send('label', { ...renamed('a', 'a'), action: 'deleted', changes: undefined });
+   assert.equal(queries.length, 0);
+});
+
+const settings = { prefix: 'P-' };
+
+test('a project moves once no repo has a PR or issue under its old label', async () => {
+   const queries = fakeDb({
+      '`project_settings`': [{ name: 'ongoing_projects', value: '["audit","docs"]' }],
+   });
+   await loadSettings();
+   assert.equal(await renameProject(settings, 'audit', 'remediation'), true);
+   const sql = queries.map(q => [q.sql.split(' ').slice(0, 3).join(' '), q.params]);
+   assert.deepEqual(
+      sql.filter(([s]) => s.startsWith('UPDATE')),
+      [
+         ['UPDATE IGNORE `project_issues`', ['remediation', 'audit']],
+         ['UPDATE `roadmap_items` SET', ['remediation', 'audit']],
+      ]
+   );
+   const ongoing = queries.find(q => q.sql.startsWith('REPLACE INTO `project_settings`'));
+   assert.equal(ongoing.params[0].value, '["docs","remediation"]');
+});
+
+test('a project another repo still labels the old way stays put', async () => {
+   const queries = fakeDb({ '`pull_labels`': [{ n: 2 }] });
+   assert.equal(await renameProject(settings, 'audit', 'remediation'), false);
+   assert.equal(queries.length, 1);
+});
+
+test('a roadmap item already tracking the new slug keeps it', async () => {
+   const queries = fakeDb({ '`roadmap_items` WHERE': [{ n: 1 }] });
+   await renameProject(settings, 'audit', 'remediation');
+   assert.ok(!queries.some(q => q.sql.startsWith('UPDATE `roadmap_items`')));
+   assert.ok(queries.some(q => q.sql.startsWith('UPDATE IGNORE `project_issues`')));
+});