Unable to scroll over an iframe

Hi, 
I need to use an iframe to display a form inside the scrollable section but the scroll doesn't work if I scroll over the iframe. 
Any way to resolve this issue?

The markup looks like that: 
```
<perfect-scrollbar>
  <div>content here...</div>
  <iframe></iframe>
  <div>content here...</div>
</perfect-scrollbar>
```
Scrolling works well over the content but not over the iframe. 