diff --git a/src/__tests__/CountUp.test.js b/src/__tests__/CountUp.test.js
index e2c7a60b..5d5eb236 100644
--- a/src/__tests__/CountUp.test.js
+++ b/src/__tests__/CountUp.test.js
@@ -60,6 +60,18 @@ it('renders with delay as a render prop component correctly', () => {
   expect(container).toMatchSnapshot();
 });
 
+it('renders with delay as a render prop component correctly', () => {
+  console.error = jest.fn();
+
+  const { container } = render(
+    <CountUp delay={1} end={10}>
+      {({ countUpRef }) => <rect ref={countUpRef} />}
+    </CountUp>,
+  );
+
+  expect(console.error).toHaveBeenCalled();
+});
+
 it('renders as a render prop component correctly', () => {
   const { container } = render(
     <CountUp end={10}>{({ countUpRef }) => <div ref={countUpRef} />}</CountUp>,
diff --git a/src/__tests__/useCountUp.test.js b/src/__tests__/useCountUp.test.js
index 370e4bce..1f409c3a 100644
--- a/src/__tests__/useCountUp.test.js
+++ b/src/__tests__/useCountUp.test.js
@@ -76,10 +76,10 @@ it('calls update correctly with hook', () => {
   const spy = {};
 
   const Hook = () => {
-    const { countUp, update } = useCountUp({ end: 10 });
-    spy.update = update;
-    spyOn(spy, 'update');
-    return <span onClick={spy.update}>{countUp}</span>;
+    const onUpdate = jest.fn();
+    const { countUp, update } = useCountUp({ end: 10, onUpdate });
+    spy.onUpdate = onUpdate;
+    return <span onClick={update}>{countUp}</span>;
   };
 
   const { container } = render(<Hook />);
@@ -87,17 +87,17 @@ it('calls update correctly with hook', () => {
   jest.runAllTimers();
   fireEvent.click(container.firstChild);
   jest.runAllTimers();
-  expect(spy.update).toHaveBeenCalled();
+  expect(spy.onUpdate).toHaveBeenCalled();
 });
 
 it('calls pauseResume correctly with hook', () => {
   const spy = {};
 
   const Hook = () => {
-    const { countUp, pauseResume } = useCountUp({ end: 10 });
-    spy.pauseResume = pauseResume;
-    spyOn(spy, 'pauseResume');
-    return <span onClick={spy.pauseResume}>{countUp}</span>;
+    const onPauseResume = jest.fn();
+    const { countUp, pauseResume } = useCountUp({ end: 10, onPauseResume });
+    spy.onPauseResume = onPauseResume;
+    return <span onClick={pauseResume}>{countUp}</span>;
   };
 
   const { container } = render(<Hook />);
@@ -105,5 +105,5 @@ it('calls pauseResume correctly with hook', () => {
   jest.runAllTimers();
   fireEvent.click(container.firstChild);
   jest.runAllTimers();
-  expect(spy.pauseResume).toHaveBeenCalled();
+  expect(spy.onPauseResume).toHaveBeenCalled();
 });