Removing Category ID from URL in conditiional?

Hello,

Currently using a category conditional within a channel:entries tag:

{if category_id == "18"} 
 
<a href="http://{path=projects}/{url_title}">Show this link if it has category</a>

{/if}

The issue is that the outputted URL is:

projects/C18/the-title-of-a-post

How can I get rid of the C18?

I have my settings in Global Channel Prefrences to:

Use Category URL Titles In Links? = no.

Thanks for your help!