diff --git a/aio/src/app/shared/scroll-spy.service.spec.ts b/aio/src/app/shared/scroll-spy.service.spec.ts
index b17e279fc32..145d288a5ba 100644
--- a/aio/src/app/shared/scroll-spy.service.spec.ts
+++ b/aio/src/app/shared/scroll-spy.service.spec.ts
@@ -54,9 +54,9 @@ describe('ScrollSpiedElementGroup', () => {
       const callInfo = spy.calls.all();
 
       expect(spy).toHaveBeenCalledTimes(3);
-      expect(callInfo[0].object.index).toBe(0);
-      expect(callInfo[1].object.index).toBe(1);
-      expect(callInfo[2].object.index).toBe(2);
+      expect((callInfo[0].object as ScrollSpiedElement).index).toBe(0);
+      expect((callInfo[1].object as ScrollSpiedElement).index).toBe(1);
+      expect((callInfo[2].object as ScrollSpiedElement).index).toBe(2);
       expect(callInfo[0].args).toEqual([20, 10]);
       expect(callInfo[1].args).toEqual([20, 10]);
       expect(callInfo[2].args).toEqual([20, 10]);