diff --git a/src/memory/search-manager.test.ts b/src/memory/search-manager.test.ts
index 991dbe619c..0b352bff20 100644
--- a/src/memory/search-manager.test.ts
+++ b/src/memory/search-manager.test.ts
@@ -22,6 +22,37 @@ const mockPrimary = {
   close: vi.fn(async () => {}),
 };
 
+const fallbackSearch = vi.fn(async () => [
+  {
+    path: "MEMORY.md",
+    startLine: 1,
+    endLine: 1,
+    score: 1,
+    snippet: "fallback",
+    source: "memory" as const,
+  },
+]);
+
+const fallbackManager = {
+  search: fallbackSearch,
+  readFile: vi.fn(async () => ({ text: "", path: "MEMORY.md" })),
+  status: vi.fn(() => ({
+    backend: "builtin" as const,
+    provider: "openai",
+    model: "text-embedding-3-small",
+    requestedProvider: "openai",
+    files: 0,
+    chunks: 0,
+    dirty: false,
+    workspaceDir: "/tmp",
+    dbPath: "/tmp/index.sqlite",
+  })),
+  sync: vi.fn(async () => {}),
+  probeEmbeddingAvailability: vi.fn(async () => ({ ok: true })),
+  probeVectorAvailability: vi.fn(async () => true),
+  close: vi.fn(async () => {}),
+};
+
 vi.mock("./qmd-manager.js", () => ({
   QmdMemoryManager: {
     create: vi.fn(async () => mockPrimary),
@@ -30,34 +61,7 @@ vi.mock("./qmd-manager.js", () => ({
 
 vi.mock("./manager.js", () => ({
   MemoryIndexManager: {
-    get: vi.fn(async () => ({
-      search: vi.fn(async () => [
-        {
-          path: "MEMORY.md",
-          startLine: 1,
-          endLine: 1,
-          score: 1,
-          snippet: "fallback",
-          source: "memory",
-        },
-      ]),
-      readFile: vi.fn(async () => ({ text: "", path: "MEMORY.md" })),
-      status: vi.fn(() => ({
-        backend: "builtin" as const,
-        provider: "openai",
-        model: "text-embedding-3-small",
-        requestedProvider: "openai",
-        files: 0,
-        chunks: 0,
-        dirty: false,
-        workspaceDir: "/tmp",
-        dbPath: "/tmp/index.sqlite",
-      })),
-      sync: vi.fn(async () => {}),
-      probeEmbeddingAvailability: vi.fn(async () => ({ ok: true })),
-      probeVectorAvailability: vi.fn(async () => true),
-      close: vi.fn(async () => {}),
-    })),
+    get: vi.fn(async () => fallbackManager),
   },
 }));
 
@@ -72,6 +76,13 @@ beforeEach(() => {
   mockPrimary.probeEmbeddingAvailability.mockClear();
   mockPrimary.probeVectorAvailability.mockClear();
   mockPrimary.close.mockClear();
+  fallbackSearch.mockClear();
+  fallbackManager.readFile.mockClear();
+  fallbackManager.status.mockClear();
+  fallbackManager.sync.mockClear();
+  fallbackManager.probeEmbeddingAvailability.mockClear();
+  fallbackManager.probeVectorAvailability.mockClear();
+  fallbackManager.close.mockClear();
   QmdMemoryManager.create.mockClear();
 });
 
@@ -145,4 +156,27 @@ describe("getMemorySearchManager caching", () => {
     // eslint-disable-next-line @typescript-eslint/unbound-method
     expect(QmdMemoryManager.create).toHaveBeenCalledTimes(2);
   });
+
+  it("falls back to builtin search when qmd fails with sqlite busy", async () => {
+    const retryAgentId = "retry-agent-busy";
+    const cfg = {
+      memory: { backend: "qmd", qmd: {} },
+      agents: { list: [{ id: retryAgentId, default: true, workspace: "/tmp/workspace" }] },
+    } as const;
+
+    mockPrimary.search.mockRejectedValueOnce(
+      new Error("qmd index busy while reading results: SQLITE_BUSY: database is locked"),
+    );
+
+    const first = await getMemorySearchManager({ cfg, agentId: retryAgentId });
+    expect(first.manager).toBeTruthy();
+    if (!first.manager) {
+      throw new Error("manager missing");
+    }
+
+    const results = await first.manager.search("hello");
+    expect(results).toHaveLength(1);
+    expect(results[0]?.path).toBe("MEMORY.md");
+    expect(fallbackSearch).toHaveBeenCalledTimes(1);
+  });
 });