Change Allowed URL Characters Error

[eluser]nuclearmaker[/eluser]
any chance to change Error Page for Allowed URL Characters to 404 page ?
i dont want user to get

Code:

<h1>An Error Was Encountered</h1>
        <p>The URI you submitted has disallowed characters.</p>

instead user will get 404 error.

any idea?

[eluser]InsiteFX[/eluser]
Create a custom error 404 page!
.htaccess

Code:

ErrorDocument 404 /path/custom404.php

InstieFX

[eluser]nuclearmaker[/eluser]
same here.still

<h1>An Error Was Encountered</h1>
<p>The URI you submitted has disallowed characters.</p>