diff --git a/src/server/createServer.ts b/src/server/createServer.ts
index bace9e2ff5..1c521b91ad 100644
--- a/src/server/createServer.ts
+++ b/src/server/createServer.ts
@@ -792,8 +792,12 @@ export const createServer = (
   const closeServer = server.close.bind(server);
   server.close = async () => {
     const results = await Promise.allSettled([closeServer(), closeProviders()]);
-    for (const result of results)
-      if (result.status === "rejected") throw result.reason;
+    const failures = results.flatMap((result) =>
+      result.status === "rejected" ? [result.reason as unknown] : [],
+    );
+    if (failures.length === 1) throw failures[0];
+    if (failures.length > 1)
+      throw new AggregateError(failures, "REA server cleanup failed");
   };
   registerCaptureTools(
     server,
diff --git a/tests/boundary/mcp/createServerCleanup.test.ts b/tests/boundary/mcp/createServerCleanup.test.ts
new file mode 100644
index 0000000000..909b0fcd67
--- /dev/null
+++ b/tests/boundary/mcp/createServerCleanup.test.ts
@@ -0,0 +1,49 @@
+import { afterEach, expect, it, vi } from "vitest";
+import { BinarySession } from "../../../src/application/binary/BinarySession.js";
+import { AnalysisProviderRegistry } from "../../../src/application/binary/AnalysisProviderRegistry.js";
+import { SessionProviderRouter } from "../../../src/application/binary/SessionProviderRouter.js";
+import { InvestigationRecords } from "../../../src/application/investigation/InvestigationRecords.js";
+import { CdpBrowserProvider } from "../../../src/browser/CdpBrowserProvider.js";
+import { EvidenceMcpServer } from "../../../src/server/EvidenceMcpServer.js";
+import { createServer } from "../../../src/server/createServer.js";
+
+afterEach(() => vi.restoreAllMocks());
+
+it("preserves both shutdown failures and retries provider cleanup after onclose", async () => {
+  const transportFailure = new Error("transport cleanup failed");
+  const providerFailure = new Error("browser cleanup failed");
+  const transportClose = vi
+    .spyOn(EvidenceMcpServer.prototype, "close")
+    .mockImplementation(async function (this: EvidenceMcpServer) {
+      this.server.onclose?.();
+      throw transportFailure;
+    });
+  const browser = new CdpBrowserProvider();
+  const providerClose = vi
+    .spyOn(browser, "close")
+    .mockRejectedValueOnce(providerFailure)
+    .mockResolvedValue(undefined);
+  const session = new BinarySession(
+    SessionProviderRouter.selectable(new AnalysisProviderRegistry([]), []),
+    new InvestigationRecords(),
+  );
+  const server = createServer(
+    { kind: "session", session },
+    {
+      browserObservation: browser,
+    },
+  );
+  const failure: unknown = await server
+    .close()
+    .catch((cause: unknown) => cause);
+  expect(failure).toBeInstanceOf(AggregateError);
+  const causes = (cause: unknown): unknown[] =>
+    cause instanceof AggregateError ? cause.errors.flatMap(causes) : [cause];
+  expect(causes(failure)).toEqual([transportFailure, providerFailure]);
+  expect(providerClose).toHaveBeenCalledTimes(1);
+  transportClose.mockResolvedValue(undefined);
+  await expect(server.close()).resolves.toBeUndefined();
+  expect(providerClose).toHaveBeenCalledTimes(2);
+  transportClose.mockRestore();
+  await session.close();
+});
diff --git a/tests/boundary/mcp/processCleanupRetryMcp.test.ts b/tests/boundary/mcp/processCleanupRetryMcp.test.ts
index fcfa70a581..0f3f6a5cb1 100644
--- a/tests/boundary/mcp/processCleanupRetryMcp.test.ts
+++ b/tests/boundary/mcp/processCleanupRetryMcp.test.ts
@@ -121,7 +121,7 @@ it("projects the retained process root through close_binary and resolves its ret
     const firstWire = JSON.stringify(failed);
     expect(failed.error).toMatchObject({
       code: "cleanup_incomplete",
-      details: { resources: ["temporary_root"] },
+      details: { resources: [root] },
     });
     expect(fault.removalAttempts).toBe(2);
     expect(fault.retryFailure).toBeInstanceOf(ProcessCaptureError);
@@ -129,7 +129,7 @@ it("projects the retained process root through close_binary and resolves its ret
       throw new Error("Expected the process scope's typed retry error");
     const retryError = fault.retryFailure;
     expect(retryError.cleanupIncomplete).toBe(true);
-    expect(retryError.cleanupResources).toEqual(["temporary_root"]);
+    expect(retryError.cleanupResources).toEqual([root]);
 
     denyRemoval = false;
     const recovered = await callClose();
@@ -185,7 +185,7 @@ it.each(["returned", "thrown", "synchronous"] as const)(
       expect(failed.error).toMatchObject({
         code: "cleanup_incomplete",
         details: {
-          resources: ["temporary_root"],
+          resources: [root],
           diagnostics: {
             primary_error: {
               details: {
@@ -207,7 +207,9 @@ it.each(["returned", "thrown", "synchronous"] as const)(
         throw new Error("Expected the process scope's typed retry error");
       const retryError = fault.retryFailure;
       expect(retryError.cleanupIncomplete).toBe(true);
+      expect(retryError.cleanupResources).toEqual([root]);
       expect(composed.cleanupIncomplete).toBe(true);
+      expect(composed.cleanupResources).toEqual([root]);
 
       denyRemoval = false;
       const recovered = parseMcpToolError(await callClose());