diff --git a/apps/cloud/src/auth/workos-callback-state.node.test.ts b/apps/cloud/src/auth/workos-callback-state.node.test.ts
index 7ba7f07458..891ce8f6a4 100644
--- a/apps/cloud/src/auth/workos-callback-state.node.test.ts
+++ b/apps/cloud/src/auth/workos-callback-state.node.test.ts
@@ -10,7 +10,8 @@
 // HTTP surface (see api.request-scope.node.test.ts).
 // ---------------------------------------------------------------------------
 
-import { afterAll, describe, expect, it } from "@effect/vitest";
+import { afterAll, describe, expect, it, vi } from "@effect/vitest";
+import { waitUntil } from "cloudflare:workers";
 import { Effect, Layer } from "effect";
 import { HttpRouter, HttpServer } from "effect/unstable/http";
 import { HttpApiBuilder } from "effect/unstable/httpapi";
@@ -21,6 +22,7 @@ import { CloudAuthPublicApi } from "./api";
 import { UserStoreService } from "./context";
 import { WorkOSClient, type WorkOSClientService } from "./workos";
 import { encodeLoginState } from "./login-state";
+import { AutumnService } from "../extensions/billing/service";
 
 // The route under test serves under the `/api` prefix in the composed app;
 // toWebHandler mounts the raw group, so paths here are relative to the group.
@@ -46,6 +48,9 @@ const stubWorkOS = Layer.succeed(
       if (prop === "listUserMemberships") {
         return () => Effect.succeed({ data: [] });
       }
+      if (prop === "listOrgMembers") {
+        return () => Effect.succeed({ data: [{ status: "active" }] });
+      }
       return () => Effect.die(`unexpected WorkOSClient.${String(prop)} call`);
     },
   }),
@@ -88,11 +93,15 @@ const App = HttpApiBuilder.layer(PublicApi).pipe(
   Layer.provide(CloudAuthPublicHandlers),
   Layer.provide(stubWorkOS),
   Layer.provide(stubUsers),
+  Layer.provide(AutumnService.Default),
   Layer.provide(HttpServer.layerServices),
 );
 
 const app = HttpRouter.toWebHandler(App, { disableLogger: true });
-afterAll(() => app.dispose());
+afterAll(async () => {
+  await Promise.all(vi.mocked(waitUntil).mock.calls.map(([work]) => work));
+  await app.dispose();
+});
 
 const run = (request: Request) => {
   // beta.59: the handler type expects a context argument; this layer stack
diff --git a/apps/cloud/src/extensions/billing/member-seats.ts b/apps/cloud/src/extensions/billing/member-seats.ts
index 1c523cfdb7..75c1d7e00d 100644
--- a/apps/cloud/src/extensions/billing/member-seats.ts
+++ b/apps/cloud/src/extensions/billing/member-seats.ts
@@ -3,6 +3,7 @@
 // ---------------------------------------------------------------------------
 
 import { Effect } from "effect";
+import { waitUntil } from "cloudflare:workers";
 
 import { WorkOSClient } from "../../auth/workos";
 import { AutumnService } from "./service";
@@ -38,9 +39,9 @@ export const reportMemberSeats = (
 /**
  * Fork `reportMemberSeats` off the calling request, mirroring how execution
  * tracking is forked: billing must never stall or fail a user-facing
- * request. Only boot-scoped services are captured (WorkOS + Autumn — no
- * request-scoped resources), so the forked fiber cannot outlive anything it
- * depends on.
+ * request. Cloudflare owns the promise through waitUntil, so the recount can
+ * finish after the response. Only boot-scoped WorkOS and Autumn services are
+ * captured.
  */
 export const forkReportMemberSeats = (
   organizationId: string,
@@ -48,6 +49,6 @@ export const forkReportMemberSeats = (
   Effect.gen(function* () {
     const ctx = yield* Effect.context<WorkOSClient | AutumnService>();
     yield* Effect.sync(() => {
-      Effect.runForkWith(ctx)(reportMemberSeats(organizationId));
+      waitUntil(Effect.runPromiseWith(ctx)(reportMemberSeats(organizationId)));
     });
   });
diff --git a/apps/cloud/test-stubs/cloudflare-workers.ts b/apps/cloud/test-stubs/cloudflare-workers.ts
index 8dc4e9c53b..e9b76e3ce2 100644
--- a/apps/cloud/test-stubs/cloudflare-workers.ts
+++ b/apps/cloud/test-stubs/cloudflare-workers.ts
@@ -7,6 +7,10 @@
 // from `process.env` into this stub at import time. Without this bridge
 // the test DbService would dial the default postgres port instead of the
 // PGlite socket server started by `scripts/test-globalsetup.ts`.
+import { vi } from "@effect/vitest";
+
+export const waitUntil = vi.fn<(work: Promise<unknown>) => void>();
+
 export const env: Record<string, unknown> = {
   DATABASE_URL: process.env.DATABASE_URL,
   WORKOS_API_KEY: process.env.WORKOS_API_KEY,