diff --git a/frontend/src/lib/document/viewer/usePdfRenderer.svelte.test.ts b/frontend/src/lib/document/viewer/usePdfRenderer.svelte.test.ts
index b9ada1c5..a72ed82c 100644
--- a/frontend/src/lib/document/viewer/usePdfRenderer.svelte.test.ts
+++ b/frontend/src/lib/document/viewer/usePdfRenderer.svelte.test.ts
@@ -186,4 +186,11 @@ describe('createPdfRenderer', () => {
 		expect(fakeLoader).toHaveBeenCalledOnce();
 		expect(r.pdfjsReady).toBe(true);
 	});
+
+	it('leaves pdfjsReady false when libLoader rejects', async () => {
+		const failingLoader = vi.fn().mockRejectedValue(new Error('load failed'));
+		const r = createPdfRenderer(failingLoader);
+		await r.init().catch(() => {});
+		expect(r.pdfjsReady).toBe(false);
+	});
 });