diff --git a/client/src/mobile/screens/admin/MAdminAddonManager.tsx b/client/src/mobile/screens/admin/MAdminAddonManager.tsx
index 898fb202a..4855a2d3c 100644
--- a/client/src/mobile/screens/admin/MAdminAddonManager.tsx
+++ b/client/src/mobile/screens/admin/MAdminAddonManager.tsx
@@ -446,7 +446,7 @@ function LlmParsingConfig({ addon }: { addon: Addon }) {
     setSaving(true)
     try {
       // Send the masked sentinel unchanged so the server keeps the stored key.
-      await adminApi.updateAddon(addon.id, { config: { provider, model: model.trim(), baseUrl: baseUrl.trim(), apiKey, vision } })
+      await adminApi.updateAddon(addon.id, { config: { provider, model: model.trim(), baseUrl: provider === 'anthropic' ? '' : baseUrl.trim(), apiKey, vision } })
       toast.success('Saved')
     } catch {
       toast.error('Failed to save')
diff --git a/client/tests/unit/mobile/admin/MAdminAddonManager.test.tsx b/client/tests/unit/mobile/admin/MAdminAddonManager.test.tsx
index 8b114e362..44e161298 100644
--- a/client/tests/unit/mobile/admin/MAdminAddonManager.test.tsx
+++ b/client/tests/unit/mobile/admin/MAdminAddonManager.test.tsx
@@ -1,4 +1,4 @@
-// FE-MOB-AADD-001 to FE-MOB-AADD-034
+// FE-MOB-AADD-001 to FE-MOB-AADD-035
 import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest';
 import userEvent from '@testing-library/user-event';
 import { delay, http, HttpResponse } from 'msw';
@@ -684,6 +684,26 @@ describe('MAdminAddonManager', () => {
     await screen.findByText('Failed to save');
   });
 
+  it('FE-MOB-AADD-035: switching to Anthropic saves an empty base URL instead of the old host', async () => {
+    const user = userEvent.setup();
+    let body: { config?: Record<string, unknown> } | null = null;
+    server.use(
+      addonsRoute([llmAddon({ provider: 'openai', model: 'gpt-4o', baseUrl: 'https://api.openai.com/v1', apiKey: '' })]),
+      http.put('/api/admin/addons/llm_parsing', async ({ request }) => {
+        body = (await request.json()) as { config?: Record<string, unknown> };
+        return HttpResponse.json({ success: true });
+      }),
+    );
+    render(<><ToastContainer /><MAdminAddonManager /></>);
+
+    await user.click(await screen.findByRole('button', { name: /Anthropic/ }));
+    await user.click(screen.getByRole('button', { name: 'Save' }));
+
+    await screen.findByText('Saved');
+    expect(body?.config?.provider).toBe('anthropic');
+    expect(body?.config?.baseUrl).toBe('');
+  });
+
   it('FE-MOB-AADD-033: whether the model reads images is a three-way choice, saved as picked', async () => {
     const user = userEvent.setup();
     const bodies: unknown[] = [];