diff --git a/frontend/src/routes/admin/system/page.svelte.test.ts b/frontend/src/routes/admin/system/page.svelte.test.ts
index 9a028cee..e0de72d8 100644
--- a/frontend/src/routes/admin/system/page.svelte.test.ts
+++ b/frontend/src/routes/admin/system/page.svelte.test.ts
@@ -9,18 +9,21 @@ describe('admin/system page', () => {
 	let fetchSpy: ReturnType<typeof vi.spyOn>;
 
 	beforeEach(() => {
-		fetchSpy = vi.spyOn(globalThis, 'fetch').mockResolvedValue(
-			new Response(
-				JSON.stringify({
-					state: 'IDLE',
-					message: '',
-					total: 0,
-					processed: 0,
-					skipped: 0,
-					failed: 0
-				}),
-				{ status: 200, headers: { 'Content-Type': 'application/json' } }
-			)
+		// mockImplementation (not mockResolvedValue) returns a fresh Response per call so the
+		// body stream isn't already-consumed after the first read.
+		fetchSpy = vi.spyOn(globalThis, 'fetch').mockImplementation(
+			async () =>
+				new Response(
+					JSON.stringify({
+						state: 'IDLE',
+						message: '',
+						total: 0,
+						processed: 0,
+						skipped: 0,
+						failed: 0
+					}),
+					{ status: 200, headers: { 'Content-Type': 'application/json' } }
+				)
 		);
 	});
 
@@ -79,36 +82,33 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		const btn = (await page
-			.getByRole('button', { name: /jetzt auffüllen/i })
-			.element()) as HTMLButtonElement;
-		btn.click();
+		await page.getByRole('button', { name: /jetzt auffüllen/i }).click();
 
-		await new Promise((r) => setTimeout(r, 50));
-		const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
-		expect(calls.some((c) => c.includes('backfill-versions'))).toBe(true);
+		await vi.waitFor(() => {
+			const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
+			expect(calls.some((c) => c.includes('backfill-versions'))).toBe(true);
+		});
 	});
 
 	it('triggers file-hashes backfill when its button is clicked', async () => {
 		render(AdminSystemPage, { props: {} });
 
-		const btn = (await page
-			.getByRole('button', { name: /datei-hashes berechnen/i })
-			.element()) as HTMLButtonElement;
-		btn.click();
+		await page.getByRole('button', { name: /datei-hashes berechnen/i }).click();
 
-		await new Promise((r) => setTimeout(r, 50));
-		const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
-		expect(calls.some((c) => c.includes('backfill-file-hashes'))).toBe(true);
+		await vi.waitFor(() => {
+			const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
+			expect(calls.some((c) => c.includes('backfill-file-hashes'))).toBe(true);
+		});
 	});
 
 	it('initial fetch loads import-status and thumbnail-status', async () => {
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 50));
-		const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
-		expect(calls.some((c) => c.includes('import-status'))).toBe(true);
-		expect(calls.some((c) => c.includes('thumbnail-status'))).toBe(true);
+		await vi.waitFor(() => {
+			const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
+			expect(calls.some((c) => c.includes('import-status'))).toBe(true);
+			expect(calls.some((c) => c.includes('thumbnail-status'))).toBe(true);
+		});
 	});
 
 	it('shows the success banner after backfill versions completes', async () => {
@@ -128,14 +128,11 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		const btn = (await page
-			.getByRole('button', { name: /jetzt auffüllen/i })
-			.element()) as HTMLButtonElement;
-		btn.click();
+		await page.getByRole('button', { name: /jetzt auffüllen/i }).click();
 
-		await new Promise((r) => setTimeout(r, 100));
-		const banner = document.querySelector('.bg-green-50');
-		expect(banner).not.toBeNull();
+		await vi.waitFor(() => {
+			expect(document.querySelector('.bg-green-50')).not.toBeNull();
+		});
 	});
 
 	it('renders the running state for import-status', async () => {
@@ -155,8 +152,9 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		expect(document.body.textContent).toMatch(/läuft|wird ausgeführt/i);
+		await vi.waitFor(() => {
+			expect(document.body.textContent).toMatch(/läuft|wird ausgeführt/i);
+		});
 	});
 
 	it('renders the DONE state with processed count for import-status', async () => {
@@ -176,8 +174,9 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		expect(document.body.textContent).toContain('99');
+		await vi.waitFor(() => {
+			expect(document.body.textContent).toContain('99');
+		});
 	});
 
 	it('renders the FAILED state with the error message for thumbnail-status', async () => {
@@ -205,8 +204,9 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		expect(document.body.textContent).toContain('connection refused');
+		await vi.waitFor(() => {
+			expect(document.body.textContent).toContain('connection refused');
+		});
 	});
 
 	it('renders the DONE state for thumbnail-status with retry button', async () => {
@@ -234,9 +234,9 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		const banner = document.querySelector('[data-testid="thumbnails-status-done"]');
-		expect(banner).not.toBeNull();
+		await vi.waitFor(() => {
+			expect(document.querySelector('[data-testid="thumbnails-status-done"]')).not.toBeNull();
+		});
 	});
 
 	it('renders the FAILED state for import-status with retry button', async () => {
@@ -261,8 +261,9 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		expect(document.body.textContent).toContain('database error');
+		await vi.waitFor(() => {
+			expect(document.body.textContent).toContain('database error');
+		});
 	});
 
 	it('renders the running thumbnail status with progress count', async () => {
@@ -290,33 +291,40 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		// Total 100, processed+skipped+failed = 36
-		expect(document.body.textContent).toMatch(/36|100/);
+		await vi.waitFor(() => {
+			// Total 100, processed+skipped+failed = 36 — at least one of these surfaces.
+			expect(document.body.textContent).toMatch(/36|100/);
+		});
 	});
 
 	it('triggers thumbnail backfill when its button is clicked', async () => {
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 50));
+		await vi.waitFor(() => {
+			expect(document.querySelector('[data-thumbnails-trigger]')).not.toBeNull();
+		});
 		const btns = Array.from(document.querySelectorAll('[data-thumbnails-trigger]'));
-		(btns[0] as HTMLButtonElement)?.click();
+		(btns[0] as HTMLButtonElement).click();
 
-		await new Promise((r) => setTimeout(r, 50));
-		const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
-		expect(calls.some((c) => c.includes('generate-thumbnails'))).toBe(true);
+		await vi.waitFor(() => {
+			const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
+			expect(calls.some((c) => c.includes('generate-thumbnails'))).toBe(true);
+		});
 	});
 
 	it('triggers import when import button is clicked from idle state', async () => {
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 50));
+		await vi.waitFor(() => {
+			expect(document.querySelector('[data-import-trigger]')).not.toBeNull();
+		});
 		const btns = Array.from(document.querySelectorAll('[data-import-trigger]'));
-		(btns[0] as HTMLButtonElement)?.click();
+		(btns[0] as HTMLButtonElement).click();
 
-		await new Promise((r) => setTimeout(r, 50));
-		const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
-		expect(calls.some((c) => c.includes('trigger-import'))).toBe(true);
+		await vi.waitFor(() => {
+			const calls = fetchSpy.mock.calls.map((c) => c[0].toString());
+			expect(calls.some((c) => c.includes('trigger-import'))).toBe(true);
+		});
 	});
 
 	it('renders the running thumbnail status without progress when total is 0', async () => {
@@ -344,8 +352,8 @@ describe('admin/system page', () => {
 
 		render(AdminSystemPage, { props: {} });
 
-		await new Promise((r) => setTimeout(r, 100));
-		// running state shown but no progress count when total=0
-		expect(document.body.textContent).toMatch(/läuft|wird|generier/i);
+		await vi.waitFor(() => {
+			expect(document.body.textContent).toMatch(/läuft|wird|generier/i);
+		});
 	});
 });