How can I change/block the Tomcat 404 page from showing?

[Gaven Ray]

I have tried to do the solution here to hide the default tomcat 404 page. It blocks the Crowd 404 page as it should. Going to https://crowd.domain/crowd/puppies shows a blank 404 page. Note not my custom 404 page but at least not the Atlassian 404 page. However if I go to https://crowd.domain/puppies it give the default Tomcat 404 page which shows the version of Tomcat. Our security team wants me to change that.