diff --git a/app/src/utils/__tests__/configPersistence.test.ts b/app/src/utils/__tests__/configPersistence.test.ts
index 7354e9a12..e93ef8480 100644
--- a/app/src/utils/__tests__/configPersistence.test.ts
+++ b/app/src/utils/__tests__/configPersistence.test.ts
@@ -457,6 +457,21 @@ describe('configPersistence', () => {
       expect(getStoredCoreMode()).toBeNull();
     });
 
+    it('logs the mode string directly, not an object wrapper', () => {
+      const spy = vi.spyOn(console, 'debug').mockImplementation(() => {});
+      try {
+        storeCoreMode('cloud');
+        const calls = spy.mock.calls.flat();
+        // Must NOT log an object like { mode } — that renders as [object Object]
+        const hasObjectArg = calls.some(arg => typeof arg === 'object' && arg !== null);
+        expect(hasObjectArg).toBe(false);
+        const modeArg = calls.find(arg => typeof arg === 'string' && arg === 'cloud');
+        expect(modeArg).toBe('cloud');
+      } finally {
+        spy.mockRestore();
+      }
+    });
+
     it('falls back to the E2E default local mode when no marker has been written', async () => {
       vi.resetModules();
       vi.doMock('../config', () => ({
diff --git a/app/src/utils/configPersistence.ts b/app/src/utils/configPersistence.ts
index 3023cf007..f3737b530 100644
--- a/app/src/utils/configPersistence.ts
+++ b/app/src/utils/configPersistence.ts
@@ -292,7 +292,7 @@ export function getStoredCoreMode(): 'local' | 'cloud' | null {
 export function storeCoreMode(mode: 'local' | 'cloud'): void {
   try {
     localStorage.setItem(CORE_MODE_STORAGE_KEY, mode);
-    console.debug('[configPersistence] Stored core mode:', { mode });
+    console.debug('[configPersistence] Stored core mode:', mode);
   } catch {
     console.warn('[configPersistence] Unable to store core mode in localStorage');
   }