Collection previous / next and featured images...

I have a collection which I use collection:previous and collection:next on to create a "prev/next item"-navigation, like so:

{{ collection:previous in "myCollection" as="item" limit="1" wrap="true" }}
  {{ item }} 
    \\ Do something
  {{ /item }}
{{ /collection:previous }}

Now, where it gets interesting is that every collection entry has a featured image that I'd like to use for this navigation:

{{ collection:previous in "myCollection" as="item" limit="1" wrap="true" }}
  {{ item }} 

    <div style="background-image: url('{{ if featured_image }}{{ featured_image }}{{ else }}/assets/img/path-to-fallback-image.jpg{{ /if }}')">
      <p>Previous item</p>
    </div>

  {{ /item }}
{{ /collection:previous }}

What I've found is that if the previous post has no featured_image, it falls back to the featured_image of the page we're currently on:

• Previous item's featured image, else:
• Current item's featured image, else:
• Fallback image

But what I'd really, really like:

• Previous item's featured image, else:
• Fallback image

What am I missing?