diff --git a/apps/hub/src/index.ts b/apps/hub/src/index.ts
index 0e490c482b..855bd36bbc 100644
--- a/apps/hub/src/index.ts
+++ b/apps/hub/src/index.ts
@@ -3366,6 +3366,22 @@ export async function createHub(config: HubConfig) {
       if (sidecarAllocationReconciliationTimer !== undefined) {
         clearTimeout(sidecarAllocationReconciliationTimer);
       }
+      // Retire the relaunch sweep's series so any in-flight pass's
+      // `.finally` reschedule is a no-op, and cancel whatever pass is
+      // currently pending. Without this the sweep outlives `close()`
+      // entirely (it's only ever re-armed, never torn down) and keeps
+      // querying `chat.workbench_launch` on a timer this function is
+      // about to end — including, once `close()` below tears down the
+      // db pool, querying a pool that's already shut down. In a test
+      // suite that boots many hubs back to back (e.g.
+      // slack-tag-mount.test.ts, CL-7453) those leaked timers pile up
+      // across the whole `bun test` process and contend with later
+      // tests' own boots for Postgres connections, which is what
+      // surfaced as `chat·relaunch-sweep: relaunch sweep pass failed:
+      // Failed query: select ... from chat.workbench_launch` and an
+      // intermittent test timeout.
+      relaunchSweepSeries += 1;
+      clearTimeout(relaunchSweepTimer);
       envCredentialPlant.stop();
       chatOrchestrator.dispose();
       workflowScheduler.stop();
diff --git a/apps/hub/test/relaunch-sweep-close.test.ts b/apps/hub/test/relaunch-sweep-close.test.ts
new file mode 100644
index 0000000000..5aa76cf37c
--- /dev/null
+++ b/apps/hub/test/relaunch-sweep-close.test.ts
@@ -0,0 +1,84 @@
+// Regression for CL-7453: createHub's relaunch sweep re-arms itself on
+// a fixed [0, 2_000, 5_000, 15_000, 45_000] ms schedule (see
+// `scheduleRelaunchSweep` in ../src/index.ts) and is never otherwise
+// torn down. Before this fix, `hub.close()` stopped every other
+// background loop (workflow scheduler, credential-expiry sweep,
+// inbox-unsnooze sweep, bench provisioner, sidecar-allocation
+// reconciliation) but left the relaunch sweep's timer running, so it
+// kept firing — and logging `relaunch sweep pass failed: ...` when it
+// queried a pool `close()` had already shut down — for the rest of the
+// `bun test` process. A suite that boots several hubs back to back
+// (slack-tag-mount.test.ts's env-gate suite among them) accumulated
+// these leaked loops, contending with later tests' own boots for
+// Postgres connections and surfacing as an intermittent test timeout.
+import { afterAll, expect, test } from "bun:test";
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import type { HubConfig } from "../src/config.ts";
+import { createHub } from "../src/index.ts";
+import { dbGate } from "../../../scripts/e2e/db-gate";
+
+const DATABASE_URL = process.env["DATABASE_URL"] ?? "";
+const describeIfDb = dbGate(DATABASE_URL, import.meta.path);
+
+const root = mkdtempSync(path.join(tmpdir(), "hub-relaunch-sweep-close-"));
+const staticDir = path.join(root, "static");
+mkdirSync(staticDir, { recursive: true });
+writeFileSync(path.join(staticDir, "index.html"), "<html>shell</html>");
+mkdirSync(path.join(root, "data"), { recursive: true });
+
+const config: HubConfig = {
+  databaseUrl: DATABASE_URL,
+  baseUrl: "http://localhost:3000",
+  sessionSecret: "insecure-test-only-session-secret-0000",
+  hubDataDir: path.join(root, "data"),
+  hubStaticDir: staticDir,
+  defaultTenantSlug: "workbench",
+  signupRateLimit: { windowSeconds: 60, max: 5 },
+  signInRateLimit: { windowSeconds: 60, max: 10 },
+  socialProviders: {},
+  allowUnverifiedEmails: true,
+  sidecarProvisioners: [],
+  envProviderKeys: {},
+  envProviderBaseUrls: {},
+  chatIdleReapMs: 30 * 60_000,
+  envCredentialPlantAdmin: {
+    email: "alice@example.com",
+    password: "password123",
+    orgSlug: "workbench",
+  },
+  signupMode: "closed",
+  allowedEmailDomains: [],
+  allowPlaintextSecrets: true,
+};
+
+afterAll(() => {
+  rmSync(root, { recursive: true, force: true });
+});
+
+describeIfDb("relaunch sweep teardown", () => {
+  test("does not run after hub.close()", async () => {
+    const hub = await createHub(config);
+    await hub.close();
+
+    const errors: string[] = [];
+    const originalError = console.error;
+    console.error = (...args: unknown[]) => {
+      errors.push(args.map(String).join(" "));
+    };
+    try {
+      // The sweep's own schedule reschedules at 0ms then 2_000ms; wait
+      // past both so a leaked timer would have fired (and, querying a
+      // pool `close()` already shut down, logged) at least once.
+      await new Promise((resolve) => setTimeout(resolve, 2_200));
+    } finally {
+      console.error = originalError;
+    }
+
+    const leaked = errors.filter((line) =>
+      line.includes("relaunch sweep pass failed"),
+    );
+    expect(leaked).toEqual([]);
+  }, 10_000);
+});
diff --git a/apps/hub/test/slack-tag-mount.test.ts b/apps/hub/test/slack-tag-mount.test.ts
index 2b5bdd9843..c0036922bb 100644
--- a/apps/hub/test/slack-tag-mount.test.ts
+++ b/apps/hub/test/slack-tag-mount.test.ts
@@ -97,12 +97,20 @@ const SLACK_ENV_KEYS = [
 ] as const;
 const savedEnv = new Map(SLACK_ENV_KEYS.map((key) => [key, process.env[key]]));
 
-afterEach(() => {
+afterEach(async () => {
   for (const key of SLACK_ENV_KEYS) {
     const saved = savedEnv.get(key);
     if (saved === undefined) Reflect.deleteProperty(process.env, key);
     else process.env[key] = saved;
   }
+  // Close each test's hub as soon as its test ends rather than letting
+  // every hub booted in this file stay live (and its background loops
+  // — relaunch sweep among them — keep running) until `afterAll`. Three
+  // live hubs contending for the same Postgres connections is exactly
+  // the kind of self-inflicted race this file should not add on top of
+  // CL-7453's fix in `apps/hub/src/index.ts`.
+  let closer: (() => Promise<void>) | undefined;
+  while ((closer = closers.pop()) !== undefined) await closer();
 });
 
 async function bootHub(): Promise<Awaited<ReturnType<typeof createHub>>> {