diff --git a/src/app/api/user/shelves/sync/route.ts b/src/app/api/user/shelves/sync/route.ts
index 0ae9459..49a8f1d 100644
--- a/src/app/api/user/shelves/sync/route.ts
+++ b/src/app/api/user/shelves/sync/route.ts
@@ -5,6 +5,7 @@
 
 import { NextRequest, NextResponse } from 'next/server';
 import { requireAuth, AuthenticatedRequest } from '@/lib/middleware/auth';
+import { prisma } from '@/lib/db';
 import { getJobQueueService } from '@/lib/services/job-queue.service';
 import { RMABLogger } from '@/lib/utils/logger';
 import { z } from 'zod';
@@ -30,6 +31,21 @@ export async function POST(request: NextRequest) {
       const body = await request.json().catch(() => ({}));
       const { shelfId, shelfType } = SyncSchema.parse(body);
 
+      // Set lastSyncAt to null so the frontend SWR refresh catches the "Syncing..." state immediately
+      if (!shelfType || shelfType === 'goodreads') {
+        await prisma.goodreadsShelf.updateMany({
+          where: { userId: req.user.id, ...(shelfId ? { id: shelfId } : {}) },
+          data: { lastSyncAt: null },
+        });
+      }
+
+      if (!shelfType || shelfType === 'hardcover') {
+        await prisma.hardcoverShelf.updateMany({
+          where: { userId: req.user.id, ...(shelfId ? { id: shelfId } : {}) },
+          data: { lastSyncAt: null },
+        });
+      }
+
       const jobQueue = getJobQueueService();
 
       // Trigger sync job with userId filter
diff --git a/tests/api/shelves-sync.routes.test.ts b/tests/api/shelves-sync.routes.test.ts
index 1a2ada7..6a82d9f 100644
--- a/tests/api/shelves-sync.routes.test.ts
+++ b/tests/api/shelves-sync.routes.test.ts
@@ -4,10 +4,12 @@
  */
 
 import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { createPrismaMock } from '../helpers/prisma';
 
 let authRequest: any;
 
 const requireAuthMock = vi.hoisted(() => vi.fn());
+const prismaMock = createPrismaMock();
 const jobQueueMock = vi.hoisted(() => ({
   addSyncShelvesJob: vi.fn(() => Promise.resolve()),
 }));
@@ -16,6 +18,10 @@ vi.mock('@/lib/middleware/auth', () => ({
   requireAuth: requireAuthMock,
 }));
 
+vi.mock('@/lib/db', () => ({
+  prisma: prismaMock,
+}));
+
 vi.mock('@/lib/services/job-queue.service', () => ({
   getJobQueueService: () => jobQueueMock,
 }));
@@ -36,6 +42,17 @@ describe('POST /api/user/shelves/sync', () => {
 
     expect(response.status).toBe(200);
     expect(payload.success).toBe(true);
+
+    // Both tables should have updateMany called to clear lastSyncAt
+    expect(prismaMock.goodreadsShelf.updateMany).toHaveBeenCalledWith({
+      where: { userId: 'user-1' },
+      data: { lastSyncAt: null },
+    });
+    expect(prismaMock.hardcoverShelf.updateMany).toHaveBeenCalledWith({
+      where: { userId: 'user-1' },
+      data: { lastSyncAt: null },
+    });
+
     expect(jobQueueMock.addSyncShelvesJob).toHaveBeenCalledWith(
       undefined, // scheduledJobId
       undefined, // shelfId
@@ -54,6 +71,14 @@ describe('POST /api/user/shelves/sync', () => {
 
     expect(response.status).toBe(200);
     expect(payload.success).toBe(true);
+
+    // Only goodreads should be updated since shelfType is specified
+    expect(prismaMock.goodreadsShelf.updateMany).toHaveBeenCalledWith({
+      where: { userId: 'user-1', id: 'shelf-123' },
+      data: { lastSyncAt: null },
+    });
+    expect(prismaMock.hardcoverShelf.updateMany).not.toHaveBeenCalled();
+
     expect(jobQueueMock.addSyncShelvesJob).toHaveBeenCalledWith(
       undefined, // scheduledJobId
       'shelf-123', // shelfId